I mostly don't like this take because it presumes a precise definition of privacy that we all agree on. And it's not even remotely close to that, which is why I think the Bluesky model is perhaps insidious.

Good point. For sake of argument, how about this stratification of privacy levels:

twitter/x/bluesky - a big tech company owns your data

mastodon - a grassroots community organization owns your data

zulip - someone you've met personally owns the data

your blog - you own the data

(and yes these are a bit of a category error, but to achieve privacy maybe we should broaden the category and sacrifice reach)