Wall hacks, yes. See my other comment:

This is definitely solvable, though. The server can only send the client location updates of players they should be able to see.

If someone tried to wall hack, they’d only see the last known location before line of sight was broken.

Giving the client that data at all is like playing Battleship side-by-side and telling the player not to look at the other board.

Aimbots are much more complicated, because the client is the authority on player inputs. Even things like latency and mouse movement can be subtly randomized by cheats to appear less robotic.