No they haven’t.

No they haven't created games with server-side net code? Yeah you've just outed yourself as having NO fucking idea how any of this works. Most MMOs are fully server-side to put that in perspective. Very few usable cheats exists for these games that are not detectable.

Server side anticheats are absolutely trivial to bypass

Server side checks/anticheats are IMPOSSIBLE to bypass short of an actual flaw in the system/code.

You're arguing that you can hack the code the server runs that you never see or know anything about. That's absurd. Hell the game itself doesn't even necessarily need to know that the server-side checks are a thing depending on the implementation. You can't fuck with code you never even have a chance to directly interact with.

Change your health in a ram editor... Server receives the state of your character... see it's invalid to the game state and drops you from the lobby/game. Do it enough times and you get flagged as a cheater, account ban. There is no "bypassing" this. Considering that game states have to be broadcast to all clients anyway, the server already has to touch all the states submitted to it anyway. A quick check on some sane things is simple and easy. A reference check from last known location to current state location and seeing that you're clear across the map or your y value is impossible... This is trivial to check.

ESPs and other client side stuff is harder since you have to send game state information to the client at some point (including information on enemies)... but you could conceivably not send status updates about characters/objects that are not relevant to a player. That would cut the vast majority of usefulness of ESP hacks.

The most important part of ALL of this discussion. Tarkov does exactly NONE of this. They check nothing. They enforce nothing. The client side anti-cheats in place are useless.