With all due respect, it’s ironic that you’re calling everyone else simple.
Something doesn’t have to be. 100% effective to be a massive deterrent. Cheat prevention is a game of cat and mouse and anti cheat is one of the levers. Here[0] is an example of a popular game with no anti cheat which was completely ruined by cheaters. Did putting EAC into the game stop every single cheater? No. But it did make the experience better for a significant number of players who were having their games destroyed by cheaters.
[0] https://www.pcgamer.com/fall-guys-adding-anti-cheat-in-the-n...