Aimbotting/wallhacks are relevant, as there are games within VRChat where those are relevant.

Due to starcraft 2's design, defogging hacks were plentiful.

Anyone who has played TF2 for a significant amount of time has run into hackers landing impossible shots, e.g. through walls

before EAC, there has been VAC (along with two separate community-ran anti-cheat services for source games), Battleye, Warden, etc. It seems universal amongst those involved, that client-side anti cheat helps way more than you expect.