That's what the {every AA one-shots non-tanks} levels of damage is for. You wouldn't want a run to even be imaginable without a tank, right?
Obviously, if a single job is overpowered, we could just scale up every other job in its role, all that the role's non-universal outputs directly interact with, and all encounter damage, right? It's not like we need even a vague modicum of inter-role balance beyond a fixedly tank perspective, surely?
What's a trinity or compositional flexibility anyways? I never understood why we needed such fancy words for "flush the healer once you have enough water pressure, duh."