I've used Linux exclusively in my private life for about 3 years now. Used it on dual-boot for the better part of the decade. The games that are currently non-playable are mostly devs who hate their users and refuse to do the bare minimum to enable Linux anti-cheat. Or have some sort or weird ideological crusade against Linux.

Steam certifies at least 70% (10% verified and 60% readily playable¹) games on their library work by default on Proton. Many of the games I play actually have a native Linux version. Many games that aren't even certified actually just work either way. And with the advent of more sturdy tooling like Heroic, Lutris and Bottles, the tinkering on those games that don't work are just simple options on a GUI. Heck, some classical old games that don't work on Windows anymore still run just fine on Proton. Making the most friendly option for abandonware.

Then there's the whole emulation scene, of which Linux has the strongest and more streamlined user experience with retroarch and a vast suite of emulation software.

Linux is perhaps the most complete, powerful, flexible and diverse software gaming platform I've ever owned.

EDIT: ¹ Of the top 10000 most played games on Steam.