As someone who just installed Linux Mint as a test and uses their machine mostly for gaming:
Linux is perfectly fine for that, too. I had one minor issue that was fixed by plugging a cord into a different plug on my machine and have otherwise had 0 issues getting things to run on the Linux partition of my system.
I actually have seen mostly better performance in the realm of about 10fps better per game than the Win 10 install on the same hardware
Spent less time tinkering with the settings (done via GUI that makes more sense than windoes' 15 different settings menus) than I never have in any version of Windows, synched my firefox over, boom.
Not gonna say Linux is perfect for everything but it does seem a lot of people think it's harder/worse than it is by a mile