I don't understand how's that any different to one-IP-one-vote.
nothing. nobody has implemented this idea before because maybe it is not "decentralized" enough.
It is completely centralized as the domain provider or domain producer (i.e., ICANN), have all voting power. You just invented a more complicated version of fiat.
Genuine question: how do nodes verify that someone was a minter? The moment someone loses permission to a domain name, they can no longer provide sufficient evidence that they minted a block, and hence, does not solve Byzantine generals' problem.