@mcc Strong agreement with this assessment.
Similarly, they have open protocols and open source implementations for the backend, but as @cwebber 's excellent writeup points out, operating a full independent instance is nontrivial, and lacking any actual full instances users could migrate to, the promises of being able to "take your account elsewhere" remain mostly aspirational for the time being.
I mostly hope that fedi/activitypub is inspired by some of the interesting bsky features...