There is a pretty strong correlation between the size of a system's game library and hardware sales. For example, PS2 had the most games and it also sold the most hardware. Of course most games on any system are not worth playing. But the more games a system has, the more good games it has too. That's why it's simply better to have more games.
Switch is now on it's fourth year and it already has a ton of games. I'd expect that number to more than double before it's all done.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox