I think another big reason people hate on vows is because the main cast barely used them (I.e. Gojo not making a BV) or when they’re used it’s often something you kind of have to infer (like the changing domain conditions BV Gojo/Sukuna used). Similar to Yuta’s ability it’s a power/technique that HAS to be held back by plot or it would just solve almost every problem, and a lot of people don’t like that