With all indications pointing towards a holiday 2024 release for Switch 2. Ngl I'm finding it more difficult to see it outselling the PS2, I think its gonna be really close, probably in the low 150M In sales but just a few million short of the DS/PS2.
I think this because I highly doubt the current Switch will ever get a price cut, the Switch will inevitably sell 140M units with 0 price cuts which is more than satisfactory enough in sales for Nintendo and is so high that the market at that point would already be so saturated to the point where a price cut wouldn't make enough of a difference in sales for Nintendo to potentially consider it and make more profit off of it, plus it doesn't help that manufacturing costs are still very expensive relative to a console in its 7th year.
I'm also thinking that the Switch 2 will have backwards compatibility with Switch 1, so if the Switch 1 never recieves a price cut, it'll likely be at a very similar price to the Switch 2 with the Switch 2 having the ability to play Switch 1 & 2 games which will lead to everyone of course getting a Switch 2 instead of a Switch 1 even if Switch 1 continues to get supported, and Switch 1 sales will fall off a cliff just like what happened to the DS after the 3DS was released.
3DS was able to sell well post Switch launch because it had its own unique library of games that you couldn't play on Switch and was over 3 times less expensive than the Switch, making it easy for people to pick up the system post Switch launch, I dont see that happening with the Switch if it never gets a price cut and if Switch 2 is backwards compatible, which I think will be the case.
If Nintendo price cut the Switch to the point where it was significantly less expensive than the Switch 2 and/or it had its own unique library of games that couldn't be played on Switch 2. There would be 0 doubt in my mind that it'll outsell the PS2. I don't think that's gonna happen tho, Nintendo doesn't seem to care about beating a milestone if there's no major financial incentive in doing so, the DS had a good chance to outsell the PS2 and definitely could've if Nintendo really tried, but Nintendo didn't seem to care and let the DS die.
In terms of my sales prediction, I'm expecting the Switch to be at 140M by March 2024, then sales sharply declining to only like 7M to be at 147M by March 2025, lifetime I'm expecting 152M sold at this point, just short of the other two.