Anti-cheat makers doesn't need to eliminate cheating completely, they just need to capture enough cheating (and ban unpredictably) that average people are mostly discouraged. As long as cheat-creators have to scurry around in secrecy and guard their implementations until the implementation is caught, the "good" cheats will never be a commodity on mainstream well-funded games with good anti-cheat.
Cheat-creators have to do the hard hacking and put their livelihoods on the line, they make kids pay up for that.
Having some anti-cheat is better than no anti-cheat but my point is it’s not a shield. It’s a cheese grater.