While I agree with you (and upvoted to match), I also acknowledge that not every game is suited for that kind of server structure. Competitive ranked games, that rely on a fair matchmaking algorithm and consistent server performance, simply can't just route matchmaking players to a random community-hosted server. And communities can't really form that way, either.
Or to make it short, esports can't do this while maintaining their esport status. And those are the games that need anti-cheat the most.
Me personally? I don't even like those kinds of games. I barely play multiplayer games at all, and when I do it's because I'm playing with friends, and couldn't care less about my rank (if I even get one). So for my kinds of games/scenarios, community or self-hosted servers are the obvious choice with zero drawbacks. But I can still acknowledge that it's not a solution for all cases.
Lo and behold, most multiplayer games do run on Linux!