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.