I would prefer communities much more than hashtags. How it would work? Similar to a profile page, but could have different users as admins (and they could change), moderator roles, each member could write on the feed, anyone could subscribe to the community. Web 3 is all about communities. It would be the perfect discovery and engagement mechanism.
People would subscribe to many communities that they are interested in and then consequently others would produce content to get free exposure (and diamonds). Also it would be perfect for the new users.