By stating what you stated, that’s called elaborating. Every video game suffers from cheaters, every single one. What happens? Developers continue to change, update, elaborate on anti-cheat code much like our fearless leaders (the Collective) do. You too can help prevent cheaters! Determine what they’re using exactly, how they’re getting around the current anti-cheat and as @Demonen stated, contribute! This is an open-source project after all.
How are you so sure of this? Each new version of existing cheats has been largely rewritten in functioning to go around the detections, and there have been longish periods where nothing known worked at all. We also have reports of cheat developers getting quite desperate whenever a new detection gets added, and their workaround for that detection (which has led to 2 full rewrites of certain cheats) getting fixed practically instantly afterwards.
Why certain cheats are still possible should be evident: they rely on functionality that isn’t possible to remove with the way a GTA multiplayer modification has to be designed, so the only way to fix them is by adding very specific detections to prevent the specific entry points they are using.
It is pretty easy to tell that you haven’t ever developed a game anticheat, since anyone who has would be able to tell that what is being done here is definitely fairly sufficient.
What? Neither of those even ban people, also most detections simply make cheats unable to work rather than banning people since common cheat developers don’t use patterns and therefore they have to modify the cheating tools for every mod update (which means that old cheats simply won’t run nor trigger detections after an update), so evidently there are barely any bans for actual cheats.