Proton is just WINE basicly.People who tried Valve's Proton say that it works really well, especially on AMD hardware (Valve and AMD are working on improving stability and performance of the drivers). Let's not make make sweeping statements without actually trying it.
What I do know is that Nvidia software is currently very wanky so that's why you are hearing these "jokes" about Linux gaming. Most people have Nvidia GPUs.
You should have the majority of AAA games working on Steam using Proton. Wine is a fallback for other games.
Linux is only free if you time has no value. I have used Unix and Linux for years, mostly for servers and my own home server runs Debian too. Usually lots of troubleshooting, but when it runs, it runs forever, pretty much.
However, I never understood why some people, especially gamers, would even bother with Linux. So many issues in general. PC games are made for Windows and Nvidia + AMD have drivers ready on release for new games. You don't get sh1t on Unix and this is why you see way more wonky stuff. It's pretty much emulation and emulation is never or very rarely perfect. Native play is always superior; You play the way developers intended.
Why would a PC GAMER choose Unix/Linux. It's just asking for trouble and limitations.
It's "okay" for casual gaming and there's always Tux Racer But if you are into hardware and buy new stuff all the time, as in high-end GPUs etc. It makes no sense to use it .. Atleast dualboot then.