I agree, the steel plate isn't a panacia. I noted that I had earlier success with cracker crust using a stone. When I came back to pizza a couple years later, I used a different flour (KABF) thinking I was improving my ingredients, therefore my quality, and found that I couldn't acheive a great crunch I had earlier. The steel helped that. But changing flours could do it without the steel, as well. I look at it as just another tool.
Actually, for me, I'm possibly more accepting of the steel since I don't have established success to rely on. But your point is well taken. I think I may have to go down from 550F to balance upper baking with the crust doneness.