Wman1996 on 30 April 2021
If we have a Game Boy/Game Boy Color situation again, I say Switch will surpass DS and PS2. The Game Boy/Game Boy Color divide is still one hotly debated. Game Boy Color had hundreds of games that wouldn't play on the Game Boy, but some games did. An Iwata Asks interview called the Game Boy Color a successor to the Game Boy, but Nintendo lumps their sales together.
So what I'm saying is that if we get a Switch Pro with hundreds of games or more that don't work on the Switch (especially some new first-party games), but it is very similar to Switch in a lot of ways we could see Nintendo combining sales again. The Pro momentum could be enough to last Switch until 2025 or beyond, and reach over 157 million units.
But if Switch Pro is like DSi or New 3DS, I don't think it will be enough. It's certainly possible for Switch to still beat PS2, but I think it will still be behind DS and PS2.
Lifetime Sales Predictions
Switch: 151 million (was 73, then 96, then 113 million, then 125 million, then 144 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 57 million (was 60 million, then 67 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima