Freedom of speech, sure. I don't know about privacy, though. Anything you post on your blog, or in the comments section of someone else's, will also end up getting scraped by robots and then aggregated and fed into the great Moloch idol of surveillance capitalism.

Savvy individuals could manage it themselves, by creating their own servers and encrypting the traffic and only granting access to trusted individuals. Most people, though, would have a hard time navigating that. A centralized (or perhaps semi-centralized, a la Mastodon) could help a lot on that front.

Perhaps something comparable to Google+'s Circles concept. I always thought that was a great idea which was unfortunately rendered completely unworkable by the unfortunate accident that it was implemented by Google.