What technological measures do you propose to block Tor and VPN services to achieve this? Not even China's Great Firewall completely achieves this, though not for lack of trying.
Device attestation is a way for a server to attest that a requester is e.g. an iPhone. Sure, it can be expanded to cover if the requester is, say, John Smith. But the server has to demand it.
Decentralized platforms tout not doing this stuff as a feature. You'd have to roll out the attestation system and require everyone running a web server to set up this attestation infrastructure; that is, the small guy running a model train forum on his laptop or whatever must risk prison time if he doesn't do attestation. That'd be so draconian that afaik not even China does it.
