Anticheat has very different requirements to antimalware.
Some interesting reads on what modern anticheats do:
https://github.com/0avx/0avx.github.io/blob/main/article-3.m...
https://github.com/0avx/0avx.github.io/blob/main/article-5.m...
https://reversing.info/posts/guardedregions/
https://game-research.github.io/ (less in detail and less IDA pseudo)