Why? There are some massive Minecraft servers (thousands of players), and Palworld is self-hostable (closer to other MMOs), so I honestly don’t see the issue. You’d have a different set of characters on each server, but that just increases the risk for cheaters who get booted.
wall-hacks
Part of anti-cheat is not sending the data cheaters use to cheat in the first place. A wall hack is possible because the client is aware of what’s beyond the wall, and that doesn’t need to be sent for anything that’s not visible. That increases computation on the server, so games tend to send more game state than is necessary for smoother gameplay.
Same applies for other ways of increasing the costs if detected
There should be a mix of elite players among the “tribunal” for determining whether someone is hacking. Players report other players, and the server should log enough to recreate the play session so moderators can review the gameplay to make a determination. A lot of cheating is pretty obvious to detect algorithmically, so this would be in a “review” scenario where it’s not so cut-and-dry.
But this takes a lot of resources, which cuts into profits, so I think studios tend to just throw on anti-cheat so they can shift blame (hey, anti-cheat didn’t catch it, we’ll forward your report). But I do sincerely believe it’s feasible for serious competitive games where real money is on the line (e.g. tournaments for prize money and whatnot) without clientside anti-cheat. For more casual games, a higher error rate is probably fine.