I’d also suggest authentication by key file.

I mean, I hate BlueSky too, but I think the reason it’s more popular than Mastodon is that it’s more centralized and in practical terms that means it’s easier to adopt and engage with.

The biggest headache I have with Mastodon (and Lemmy, to a lesser extent) is defederation. I understand it’s the most practical thing to do sometimes, but it’s waaay overdone. Like, there needs to be a culture of only defederating as a last resort due to pratical concerns (e.g. bots I guess). Unfortunately the current culture is one where many instance admins treat defederation as a personal blocklist. I wish more admins would leave it to individual users to decide who to allow or not.