[meowkit]

https://docs.ens.domains/learn/protocol/

Supporting DNS all up should be possible but organizing the other decentralized services (compute, storage) is the hard part

[fruitworks]

The name service is easy, namecoin did it more efficiently than ENS a decade ago.

The decentralized services need not be attached to some blockchain due to the resource constraints. But there are examples like Filecoin and such.