Aimbots dont need to do a lot to provide advantage at the highest level. Moving “perfect aim” from 1x1 pixel to 3x3 pixels, but with 33% probability would provide a huge advantage and be undetectable.

Modified assets cannot be verified unless you lock the system down, like an Xbox. On a PC? No way. You can combat it by sitting in ring 0 (which is what anti cheat software does) but you couldn’t just check some checksums.

In terms of aggregating data and spotting something like see-through walls, there isn’t the statistical method to discern between great intution built over years of playing the same map and having see through assets.

I used to work in AAA game development, across most of low level (graphics, networking, memory, assets etc) so unfortunately I know this problem is nigh on impossible to solve unless you have a locked platform.