Exactly this, which is the problem with all modern accounts. No person to talk to so you can understand what happened and maybe fix it.
replyThey most definitely have a person to talk to. They're not the largest Google Cloud user by far, but they are large enough to have human account reps.
replyAnd those reps might not be told what the reason is.
replyThey also don't want to tell you because then they have to put rules and cannot ban people arbitrarily.
replyGiving reasons is putting accountability on Google and they don't want that.