The Switch is the platform that I bought the least number of third party games.

b/c being confirmed will now entice me to buy them

I think there's a market for those who want to play games for achievements/trophies so having a similar system would entice people to do so.

Having the option to play portable or docked is great - power is holding back which is the main issue.

Some reasons why players purchase less 3rd party games (on a per game basis) than on other systems:

1. Players tend to purchase games on Non-Nintendo Systems because historically, Nintendo's have proven to be the one that are the least reliable in regards to availability. This behavior has been habitualized.
2. (Too) much weaker hardware has naturally hindered the engagement of 3rd parties on Nintendo systems, which feeds into point 1
3. Games that do release are basically guaranteed to look and run noticable worse, offering an objectively inferior gaming experience, due to them not being made for that much weaker hardware originally. Many people arent willing to trade the experience with the game for a gimmick that's only cool for a couple of uses or portability whereas there are fewer people that view portability as a necessity.
4. Nintendo markets their systems in a way that puts themself at the front center with little to no room for others to shine. This causes people to associate Nintendos system primarily with Nintendo's franchises, turning them (at least partially) blind to whatever else there may be.

Do the reverse to get more people to buy 3rd party games on your system

Nintendo kinda addressed this in their most recent fiscal quarter briefing. They are emphasizing strengthening relationships with 3rd parties and cite 3rd party software has been more than half of physical Switch software sales since 2020:

They also cite working more closely with 3rd party devs, having cheaper dev kits, working better with them on the development side, and supporting things like Unreal Engine. Bolded are comments direct from Nintendo's financial briefing: 

"Thanks to these efforts, our partnerships with software publishers are now stronger than ever."

"As a result, about half of the software units sold since the fiscal year ended March 2021 are titles released by other software publishers. This figure does not include the numerous download-only titles that have been released by software publishers. Sales of both first-party titles and those released by other software publishers continue to achieve high levels of sales."

But that's pretty sizable as far as I can tell, that's more software sold than say the Playstation 3 that had obviously a ton of third party support and likely more than XBox, with 3rd parties getting more than half of the pie for several years now. 

When all's said and done, Switch will have pretty close to the same number of software sales as the PS2 (it won't be PS4 level) ... but PS2 level is not freaking bad. If 3rd parties are getting a significant cut of that, that's quite good. 

On Switch 2 it has room to grow if devs want to bring some of their bigger IPs (Call of Duty is already guaranteed by contract, likely will see things like Madden NFL and Street Fighter return, possibly even mainline Final Fantasy and Resident Evil). Nintendo will not likely be able to maintain their software release pace either once they transition up to PS4-PS5 style visuals, which means 3rd parties will have more pie to eat. Like I doubt you are getting 4 distinct Legend of Zelda games (BOTW, TOTK, Link's Awakening remake, Echoes of Wisdom) Likely with Switch 2, 3rd parties will have more than 50% of the software split. 

Well the sales are good (overall) but also show the problem.

Nintendos 1st party sales make up around 50% of all sales, which means that only around 625m-ish games come from 3rd parties.

However, sony only has aprox. 60m 1st party software sales (going by chatGPT, if anyone has a more accurate number, please tell).

Given that the PS2 sold around 1.383billion software, that's a 3rd party share of ~ 95% = 3rd parties sold almost twice as good on ps2 compared to Switch.

If we factor in that Switch has much more software to offer, we can fairly safely say that those 625m are spread across more devs resulting in even

less sales on a per game basis.

Most of those 3rd party games are of a smaller budget and don't need to sell 10 million to be a success. Even 50k for some indie games is a success.

Maybe.

Noone (of us) knows how much each game has to sell until the sales reach satisfactory mass.

What we can tell however is, that the sales potential is ~ cut in half on switch compared to PS2 and I have the feeling that this is also the case with the current competition.

But if you are a developer with limited resources, which platform are you going to choose?

The one where 80%+ of all sales are 3rd party, or the one where only 50% are? Assuming that overall software sales are similar

Well you can look at it as if Nintendo's userbase for third parties then is a healthy 73 million install base (half of 146 million) all to 3rd parties with a high attach rate. 

That's significantly larger than XBox One or XBox Series S/X, and larger than past Nintendo systems like the Super NES. The software attach rate would also be way more favorable than a system like the 3DS, which sold about 75 million units but only 392 million pieces of software, Switch by comparison is at like 1.3 billion, so even just below half of that is like lets say 610-615 million just for 3rd parties, that dwarfs all Nintendo + 3rd party software for the 3DS (at higher console style software pricing too, another thing 3rd parties will like). 

That's still a lot of systems and a lot of games sold basically. 

Next time around too the proportion of 3rd party games being closer to 50% or better will likely impact the Switch 2 earlier in the product cycle as with Switch 1, it didn't have a ton of the better 3rd party support until later in the product cycle because Nintendo was coming in off a low point after the Wii U and 3DS (underperformed to expectations). Games like Monster Hunter Rise, The Witcher 3, Persona V, Nier Automata, Dragon Quest XI, Mortal Kombat, etc. only started appearing several years after release. EA only released the modern engine FIFA/FC Soccer last year (Frostbite Engine). 

Switch 2 will likely see much stronger 3rd party support from day 1, and I think the split may eventually become 60% third parties, 40% Nintendo, which is what it used to be on the SNES/Super Famicom. As I said Nintendo probably won't be able to release as many games to begin with on a yearly basis as games will be more expensive and take longer to develop with the significant leap forward in visuals. 

The other factor is the old 3rd party Sony dominated hierarchy is ending. Whereas in the PS1/PS2 days, Sony could lock away IPs like Final Fantasy and Metal Gear Solid and keep them away indefinitely from other platform holders, that whole status quo is basically ending. Square-Enix is even reiterating again this week they have to get the Final Fantasy games on other platforms as soon as possible. Sega, who in the past looked off Nintendo platforms for the Yakuza series is now saying that after finally releasing an installment of the series on Switch that sales are way past their expectations. Etc. etc. Game development is so expensive that 3rd parties can't keep games locked on 1 platform any longer, even Sony doesn't want to do that anymore. The landscape is much more favorable for Nintendo now. 

I can only hope that it happens as you describe.

Because nothing's worse than having to buy a 2nd system for multiplatform games, which should have been on the 1st sys to begin with.

And yes, the 3DS wasnt exactly a good system. Not only is it one of those with the lowest unique user count

( UUC = hardware sales / avg # of systems per User ) but also very low software sales in general. The one thing that saved it from drifting into

Well I'll be honest for game consoles, I think Playstation will basically remain the defacto 3rd party platform for highest sales.

But Nintendo can carve out a pretty sizable audience in that regard, like just shy of half of 1.45 billion pieces of software is like 650 million copies of games ... that's probably not far off from what the XBox 360 had for 3rd parties and higher than the XBox One and Series S/X.

Also goes to show what a software dud the 3DS was ... only 392 million pieces of software from 75 million systems sold ... assuming lets say a 55/45 split for Nintendo/3rd party there that's only 176 million in 3rd party software sales (and I'm probably being generous with this split) on 3DS ... you can see why a lot of 3rd parties that early on made promises for big 3DS support kinda bailed out as the product cycle went along.

Switch being at like 625 mill+ 3rd party software is way different. If Nintendo can get to about 700 million 3rd party pieces of software sold in a generation, that would be really, really good. Probably not far off from a system like the Playstation 3 (I'm assuming maybe a 20/80 split there for 1st-2nd party/3rd party on PS3 and PS3 had massive 3rd party support.

Nintendos first party offerings are so strong that customers can satisfy their gaming needs just on Nintendos products.
The main reason I buy 3rd party games on my switch is the convenience of having them on the go and if they are very cheep. Indie games work well in this regard since they often cost less and have a certain uniqueness about them that can spark interest when browsing the shop.

Generally, offer better deals/products than the competition. Many third party games runs better on other hardware making them a harder sell on Nintendo systems. If it is the only system one own they still need to beat the first party offerings.