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)