Keys vs passwords. Pretty good article on the subject:
https://open.substack.com/pub/subconscious/p/trustless-protocols-are-better-than
>You can always implement key custody on top of user-owned keys. If you want key custody, you can have key custody. If you want a cold wallet, you can have a cold wallet. Trustful protocols bake assumptions about authority directly into the infrastructure. Trustless protocols give you the choice.
The great thing about Fediverse is that we can have both traditional identities and identities based on keys.