People tend to generalize, but what they probably mean is "it's not reasonable for gaming for the games I play.
I haven't fully switched over yet because the games the combo of the hardware I have + the games I play regularly, still give me issues vs. Windows. Getting them to run isn't the problem, but I haven't been able to solve miscellaneous crashes, lag, lower frame rates, etc.
My next PC upgrade will probably be getting rid of my Nvidia 1660 super and getting something AMD for less headaches.