Hashtags have been pretty helpful to me on Mastodon. If people tag their stuff with the tags I follow I get a chance to see me stuff and follow new people organically, while people who didn't want to be discovered never hit my radar. Making that kind of topic tagging easier for people to apply might be useful, as I've seen new arrivals to the Fediverse who can't figure out why nobody sees them until someone tells them to tag their stuff.