The best combo is probably PC + Switch 2 or PC + Steamdeck or some other Pc handheld.
With PC you get access to the vast majority of third party games, everything from MS and increasingly more Sony games. On top of more indies than any other platform and the best backwards and forward compatibility.
Then you either add a Switch 2 for the portability and access to Nintendo games or a Steamdeck (or similar) where you don't get Nintendo games but you get to carry over your entire PC library, and get stuff like Cross progression which is nice.