Linux

For Steam games, it's simply a matter of checking the "Enable Steam Play for all Other Titles", and you're all set. Depending on your library, 50-80% will work with no discernable difference, besides maybe a slightly longer download and open time. Check out protondb.com which will give you an idea of how many you can expect to work at least somewhat, including using your own Steam public profile if you wish.

Some games will need a couple small tweaks, ie a specific Proton version to manually copy in, a game setting like Borderless Window, or worst case a few terminal commands but they are set and forget in every instance I've encountered. Protondb has comments of others who will share their experience and sometimes how they got something to run well if it doesn't out of the box.

Non-Steam games also work. Lutris is the easiest way to set it up, but it can be done manually too. Both wine and proton will work, let me know if you want a tutorial for manual set up but it's too long for one comment.

Now for issues:

Drivers are okay for most general stuff (mic, headset, mice, keyboards, gamepads), specialized stuff requiring proprietary drivers is a crapshoot. I've a 2nd hand DAC I can't use on Linux for Rocksmith.

Games that will not work and likely will never rely on invasive anticheat. So it's a waste of time to try and run Rainbow 6 Siege, Fortnite, Valorant or League of Legends. Without the anticheat the games could run perfectly fine.