Ah, yes, sorry. I mixed up my terminology a bit there, good catch. Every instance of “round” in my comment was supposed to be “turn”. I’ll edit it. But yes, sneak attack is also once per turn, and not round, which is very odd. It honestly seems like an oversight that just happily caused the balance for the rogue to catch up a bit. Rogue doesn’t really have any ways to consistently trigger it, and while it seems like it might be a case of “extra attacks should get the same effects as regular attacks” (if that makes sense to you) then it is extremely odd that the Barbarian’s advantage from Reckless Attack doesn’t last for the round, only for your own turn. So AoOs don’t have the advantage.