An iPhone can communicate with other devices over open protocols, which is different from the proposed un-reachability and privileged access to the network.

Ah, I’m not giving a full picture there. Technically you can use layered encryption like tor uses on the clearnet. Tor additionally exposes tor-only services that route exclusively via tor’s onion routing (not just http wrapped inside an encryption onion).

i2p works differently under the hood, but the shared piece is exclusive services, only accessible through a non-standard protocol. That’s how you’d get a different web. Unless we’re talking physical layer stuff.