You make a good point, that Roman Reigns is not over like that but on the other hand The Rock and Austin are once in a lifetime level guys that just so happened to come through at the same time. Gotta take that into consideration.
Even if Daniel Bryan was on Austin/Rock level, he's just one guy and the way the whole product is being handled is
so I can't really agree with dudes wondering why CM Punk or DBry can't do Attitude Era numbers. The product just isn't there, so there's no way for one guy to take it there.
Roman has a ways to go, but exactly as you say now he's "not awful" and I believe he has a good foundation to build on.
Either way, I think Dean Ambrose has more potential from what I've seen so far.