"Domain registrars are more vulnerable than private keys, as they can be compromised, social engineered, or coerced. But your Ethereum private key is under your control.

Similar to how Vitalik used Ethereum to prove he was alive during a death hoax, you can use your Ethereum identity to prove domain ownership and control of both the domain and the Portrait without relying on centralized intermediaries."

https://portrait.so/blog/verifying-domain-ownership-on-ethereum