Gaming on Linux for me started getting easy for me around WINE 3.0-ish, when EverQuest (and other MMOs of that time period) started running pretty near flawlessly for me. That's when my Windows XP/7 partition finally died for the last time on my system. Ain't been back to Windows since (other than trying out Windows 10 on a friend's system and instantly remembering why I had learned to hate Windows). Since Steam came to Linux and Valve released Proton, it's all only gotten better by leaps and bounds.
But damn I am grateful it exists. It single handedly allowed me to have Linux and nothing else on my personal machine.
Gaming on Linux for me has been more than tolerable, it has been as close to perfection as I always hoped.