I don’t know much about anti-cheat development, but it can’t possibly be that hard to at least implement something that checks whether a player even could have done something in a certain amount of time which would eliminate a lot of speed related cheats, and for the rest, why not look at data averages to try to weed out cheaters?
I know combing through the data is probably complicated, but so is installing kernel level anti cheat software that has to monitor every single process running on a person’s computer.
There was a pretty big work around for that, as long as only one person is in “online” mode on Steam, you can technically have infinite people playing at once. Of course that only works if most people want to play a single player or local LAN game.