I think the problem is that that kind of work requires a good deal of developer resources for a long time. What company wants to pay upkeep on a shipped product? You could save hundreds of thousands of dollars a year by shipping a rootkit to players and not worrying about server security.
I suppose Valve, who trained a neural network to detect/ban cheaters exhibiting unnatural behavior.
It hasn't paid off very much, CS2 still has a rampant cheating problem. VAC has been a joke for years at this point.
Because CS2 does not have Overwatch, the AI VAC thing.
As far as I know is only enabled on Dota.
VAC is a joke until they ban players and all start to cry on reddit/discord.
It only needs to be good enough that people keep buying (or not) the Prime when their old account gets banned. There is good reason that it exist, also from cheating perspective.
Any company that makes big money on
long-living multiplayer games?
It would not only take a lot of developer resources, but also computing power.