I am essentially in this exact role. The junior developers simply don't have the experience to evaluate the output of the agents. You wind up with a lot of slop in PRs. People can't justify why they did something. I've seen whole PRs closed, work redone, and opened anew because they were 70% garbage. Every other comment was asking "why is this here? it has nothing to do with the ticket."

Sadly, this is not sustainable and I am not sure what I'm going to do.