We could ask why not any other *buntu distro. Ubuntu is simply the default / most popular / most well known. Also, comparing desktops, Ubuntu seems modern (UI / UX) while KDE kinda gives me Windows 2000 vibes. I really prefer nice UI so KDE is just not pleasent to (my) eye.

I had that for some time, but it was a bit of a hassle… I could, but I found myself rebooting more than I wanted to, to switch OS.

It was possible before they introduced kernel-level anti-cheat. Now there is no way, AFAIK. Besides, there is also the elephant in the room that it’s not trivial to set up, and can break at any update of any component. When I want to go play, I expect to play, not to fix problems. It needs to be officially supported or you simply might end up fixing stuff instead of playing, which beats the entire purpose of gaming to relax.

League of Legends still doesn’t support it. Most of my friends play it however shitty and toxic it may be. As long as that remains a fact, I can’t move to Linux unless I want to “sit outside and look at my friends playing together”.