With the successor apparently delayed to 2025, I'd say it has a shot, but it really depends on how Nintendo handles it post-replacement.
If they keep it around as a budget alternative like they did with the 3DS it can reach #1, but I kinda expect they will treat it more like Sony treated the PS4 and phase it out relatively quickly to encourage people to upgrade, so if I had to guess now I'd say it lands at #2.

Yeah.

3DS to Switch was a little similar to the PS3 to PS4 transition. It made plenty of sense to support the old platform a little because the new one wasn't backward compatible. 3DS being more obvious as a pure handheld and a distinct experience from Switch. 

Unless Nintendo is foolish enough to have no or limited backward compatibility on Switch 2, Switch will only serve as a budget option before it's killed off. 

Switch surpasses the PS2 in NA, but DS is tough to reach. I'll also guess #2 right now. 

Unless Canada and Latin America make up for the U.S. and then some, then probably not. The deficit against the DS is just too great. Let's say the Switch sells 3.25M this year in the U.S. It will be sitting at about 47.5M (there is a slight margin of error). Meanwhile, the DS sold 53.5M units lifetime in the U.S. That means the Switch will need to sell at least another 6M or so from 2025 onward just to tie the DS. Absolutely no chance of that. Once the Switch 2 releases, the Switch is going to drop like a rock, as is normal for a Nintendo system once its official replacement is released. It'll probably end somewhere around 49M at the end of its life, maybe 50M tops.

The U.S. alone has generally been between 86% and 90% of Nintendo sales for the region (usually towards the mid to low part of that range), so if the Switch does hit 50M in the U.S., its total for the region could get to somewhere in the 55.5M and 58.2, still short of the 59.93M for the DS. So, it could probably come close, but it's highly unlikely to. That U.S. deficit is just too big. Not saying it's impossible, but it is a long shot. Perhaps the only way it does is if Nintendo doesn't drop it like a sack of potatoes after this year like they normally do when they release a system's official-official successor, and even then it will be an incredibly narrow victory.

It should still pass the PS2 some time in Q4 of this year, though, which would make it the new #2 system ever in the U.S., which is one hell of an accomplishment.

I feel like Mexico can be a big boost for North America. Looking how Mexico did with the Mario Movie, it seems like a reasonable idea that more units can be sold in Mexico compared to Canada. 
Though I do believe that the Switch does need a cut in price in Mexico and the Latin countries. But the Mexican market seems untapped and has great potential.

The Switch will not pass the DS in NA. This isn’t even up for debate. We’ll likely see 2-3mil during calendar year 2024 for Switch, and sales will absolutely plummet following this year (regardless of whether Switch 2 is a flop).

Could it pass PS2? It’s certainly on track to sit right around 53-54mil LTD, so it’ll be very close. But I think it’s possible.

That's okay that you don't think so. So you think that Mexico wont hop on the Switch train during its last couple of years? The successor is going to be more expensive than the Switch. Personally I think Mexico will show greater interest in the Switch (especially with price cuts).

I think people are underestimating how many switch consoles I (a proud U.S. citizen) would buy when the paper Mario remake comes out, if I didn't already own a Switch. Unless they predicted I would buy one, in which case they'd be right on the money.

When it comes to the total sales in the Americas, which combines South American & North American sales. I believe the Switch will outsell both the PS2 & DS eventually.
The Switch in the Americas is currently at 53.58 Million while the DS sold 59.93 Million in the Americas. So the gap currently is quite a bit smaller for the Americas compared to the U.S only sales, as it seems like the Switch is doing better than the DS in the Latin American regions. The gap is only 6 Million between the two, this fiscal year the Switch is expected to sell around 5.8 Million in the Americas which will put the Switch at around 54.8 Million Units by March 2024. If we were to forecast a 35% drop for the next fiscal year, which is a decline that seems reasonable by most people here, the Switch would sell around 3.8 Million for fiscal year ending 2025 putting the Switch at 58.57 Million by March 2025, only around 1.4 Million away from DS's sales in the Americas, even if the Switch drops off hard after March 2025 it should still be able to crawl past the DS in sales to become the bestselling console in history for the Americas. I'm expecting the Switch sales to end at around 61-62 Million units in the Americas when all said and done, making it #1 all time.

When it comes to North American sales only however, it does become a bit more tricky for the Switch to surpass the DS mainly because the Switch hasn't been keeping pace with the DS in U.S-only sales and it's becoming difficult to see the Switch being able to surpass the DS in the U.S this late in the game. The Switch is at around 44.5 Million in the U.S as of December 2023 while the DS sits at 53.53 Million, still a 9 Million gap left between Switch & DS in the U.S. The Switch sold around 5 Million Units in the U.S in 2023 and assuming we're predicting a reasonable 35% drop in 2024 the Switch would sell around 3.25M in 2024, putting the Switch at around 47.75 Million by the end of 2024, still nearly 6M away from the DS. Since I'm expecting no price cuts for Switch and Switch 2 BC I find it very difficult to see Switch from there on out to see another 6 Million the rest of its life to surpass the DS in the U.S since sales will drop off a cliff once Switch 2 releases. I'm expecting the Switch to sell around 50-51 Million units in the U.S when all said and done.

With the chnaces looking less likely for the Switch to outsell the DS in the U.S, it's gonna need Canada, Mexico, and other Latin American countries to carry the NA sales a bit more to have a chance to outsell the DS in NA, which I think it's certainly possible. Based on recent NPD sales estimates along with Vgchartz estimate, it seems like the Switch has recently just narrowly outsold the DS in the non-U.S portions of NA, with the Switch approximately at 4.5 Million in sales while the DS sold around 4.4 Million outside the U.S in NA. Nintendo also recently stated that a higher proportion of their American sales are coming from non-U.S countries and specifically mentioned that Switch sales in Mexico are up YOY thanks in part to the Mario Movie and related marketing getting the other less marketable countries more interested in the Switch.

Assuming the Switch sells around 50 Million units in the U.S and we use the 90% U.S Sales to 10% Other NA Countries sales proportion that's been a standard for most of the Switch's life. The Switch would sell around 55 Million in NA, just short of the DS's 57.9M but considering the proportion of sales as of late been leaning towards Mexico and other Latin American countries, it likely will be a bit closer than that. Right now i'll give a guess that the Switch will fall just short of the DS in NA selling around 56M, but it could go either way.

It should be able to comfortably outsell the PS2 in NA & the U.S however, it could happen as early as the end of 2024 but it should outsell it by Q1 of 2025 at the very least. Which will make the Switch the bestselling home console in North America's history.

Your synopsis is well-rounded. Outstanding.

I agree that South America and Mexico will be what push Switch to be the best selling in the Americas. The US market seems rather "full", with other console options, other game options, lack of money, and less children. 

On a different note 4.5M doesn't seem like a lot for 26 countries. Granted it is a population 656.24M people with citizens that have different priorities than the average US citizen. I was gonna compare it to China which sold 4M as of Dec 2021 (are they still selling in China?), but China has 2.2x more population so its not a fair comparison.

So for Nintendo to start selling more outside the US, Nintendo needs to get more advertising out there? Hopefully the Legend of Zelda movie can come quickly (obviously done with care). I think something Nintendo can do is to place region specific price cuts. Like Mexico, Central America and South America would receive a 15% price cut for all versions of Switch ($169 Lite, $259 Switch, $299 OLED), and 10% off Nintendo software. (This is me being too optimistic). The Latin countries are the Switch's hope to surpass NDS and PS2. Mexico is the Switch's hope to surpass the NDS and PS2 to become the best selling NA console. 

I feel like more of the reason why it'll be a bit difficult for Switch to outsell the DS in the U.S is mainly because the DS was a handheld only device, which means that consumers were more likely to buy a DS for themselves rather than sharing it with a family like you would with a home console, so handheld sales are always bound to recieve a bit more sales because it is less likely to be shared and purchased per person rather than per family. My household brought 4 DS consoles alone because my family members all wanted their own personal DS, and I upgraded with a new DSI model. 

The DS was also just far cheaper for most of its life which certainly helped as well, it was very easy to buy the DS as an impulse buy product.

The Switch doesn't have these advantages as much, yea the Switch is a part handheld as well and I'm sure there's a good deal of household with multiple personal Switch's, but the Switch also being a bit more pricey and having a home console form makes it more likely to be a device to share amongst a household rather than having multiple people buying them on an individual basis.

If the Switch gets a good price cut however, I'll say it's far more likely for the Switch to outsell the DS in the U.S, I just don't think Nintendo is gonna do it with the Switch and I think they're gonna want to just force people to buy the Switch 2 which likely wouldn't be that much more expensive than the 300$ Switch.