1. Has an actual path to adoption (because people have keys and have a motivation to try hard to retain their keys because they have crypto assets)

2. Once smart contract wallets properly gain adoption, you'll be able to do recovery (see: https://vitalik.ca/general/2021/01/11/recovery.html )

3. Lots of built-in anti-sybil techniques (eg. verifying that the address has nonzero balance is a pretty simple and effective one)

1. A lot more people are using Sign In With Ethereum than other kinds of signature-based auth to log into websites. The UX, while not perfect, is a lot more figured out.

2. SIWE lets the user share a cryptographically verified shared state of the user. For example, digital asset collections, reputation in a group etc.

Isn’t sign in with U2F exactly the same guarantees and issues? (Cryptographically proven pseudonymous identities, but no recourse if you lose your keys)

Why does ethereum need to come into the picture?

You can't assign value or tokens to public keys without a blockchain, we've come full circle.

People are actually using it.