Lag compensation makes the absolute minimum relatively high. For example you need the client to know about an enemy player behind them that doesn't get rendered

Lag compensation makes the absolute minimum relatively high. For example you need the client to know about an enemy player behind them that doesn't get rendered, because the client can turn around faster than the server can tell them about that player. Otherwise it can lead to a super frustrating experience where the enemy player pops into existence on the client in the middle of the screen, and you couldn't have reacted because there was nothing there. So if you're sending that data to the client, well now cheats can look for that and detect if there's a player behind you and warn you, giving an advantage. The same thing applies to corners and other occlusions, just less extreme, but still just as frustrating.