it's not that big an innovation to be able to easily migrate your data from one silo to another. facebook and google have been letting you download "your data" for years. i'm sure that a simple application could be made to do a lot of it. sure, the silos don't let you add data to the profile with your chosen datestamps but aside from that it's still the same.
"relay in the phone" means a centralisation resistant protocol that can operate at that level where a tiny node can participate and not be excluded or unreachable.
it really doesn't take that much study of distributed systems theory to understand why nostr is not an innovation yet, celebrating it as a cure for centralisation is extremely premature.