I think by the end of your message you were starting to arc around a little bit to the right way you need to think about clients: as outside your security envelope. (TPM is a joke in my mind, just like client side anti-cheat.)
There are many ways to try to identify and stop cheating on the server side that have not been explored because executives have directed use of off-the-shelf anti-cheat because they do not understand why it is snake oil.
You don’t necessarily need to detect the cheat itself, you can look at things like players having suddenly higher kill rates and put them into a queue for observation by either more advanced (more expensive) automation to look for cheating or eventually involve a human in the loop.
Even on consoles after a while it becomes obvious that you cannot control the hardware, let alone the software on the client side. Those are the very best argument for this kind of approach and they get cracked eventually.
Actually, I am.
Using rootkit anti-cheat is a shortcut that reduces cost for both dev time and hosting time at the expense of your customers’ security and CPU. You also have to lay your cards on the table for those who are attacking you. It is not the right solution for this problem.
Authoritative servers. Never trust the client, especially with information the player shouldn’t have right now. Look at behaviors and group players based on if you think they cheat or not - let the cheaters play together, no need to spoil their fun and let them realize you know they cheat.
People do some or all of this on the server now, but root kitting all machines to try to solve this problem to play video games is one of the dumbest approaches ever and we will realize it one day when a state level actor pops their zero day against a big install base.
Stop stealing our CPU cycles for high risk rootkits and start mitigating and detecting cheating on the server.
It’s that easy.
I stopped playing games that want this bullshit. Don’t need that shit in my life.
Or, if I can extract that key from the hardware, I can pretend to be that hardware whenever I want, right?