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.