I don’t know about Ubuntu specifically, but generally on Linux gaming has improved a lot. You can check protondb.com for info on how games run under Linux. I’ve been using EndeavourOS with KDE and standard kernel for almost 2 years now and have had some issues with some games but always managed to resolve them. I played through Steam, through Lutris (gog.com games).
I don’t know about Ubuntu specifically, but generally on Linux gaming has improved a lot. You can check protondb.com for info on how games run under Linux. I’ve been using EndeavourOS with KDE and standard kernel for almost 2 years now and have had some issues with some games but always managed to resolve them. I played through Steam, through Lutris (gog.com games).