In my view the atproto approach asks the users to make fewer required complex decisions, but gives them the freedom to make many voluntary ones. If someone wants to use a particular application, they basically just need to sign in. If they don't have an existing ATProto account, they can just make one, in the flow of the application they're signing into. Later they can chose different clients, or different infrastructure, or move their account, to their own hosting even if they want.
Mastodon requires a complex decision upfront, which server do I trust, which is analogous to where you create your account on ATProto, but unlike ATProto, doesn't give the tools to seamlessly transition later.
The trust lens I think is a good one. You want to let different users make different tradeoffs in effort without having that leading to a worse experience..
