Hate to say, but might actually be a legitimate use case for blockchain here. Identity provider which is responsible for being a source of truth on aliveness tied to a smart contract for paying annual registrar fees.

Though the traditional way would just be finding a registrar which can direct debit (e.g. CSC Global or MarkMonitor) or setting up a trust account for someone to manage it for you. Or just power of attorney plus escrowed account.

Apart from cryptocurrencies, I don't think that there are any legitimate use-cases for blockchain.

Then the question is whether we want cryptocurrencies or not (I don't).