Gaming on Linux is definitely there. Most people saying otherwise simply haven’t tried it recently enough. For the last year or so, the experience has been largely flawless. There’s the occasional game that needs a flip to Proton Experimental or a launch option; even more occasionally the need for special Proton until Valve’s version catches up. But the work that has been done to get Linux gaming at parity with Windows definitely shows.
Frankly, on AMD, the experience is better than Windows. Less overhead and never have to worry about video drivers since they’re in the kernel. I’ll happily switch to Experimental occasionally as a tradeoff.