which server?
there are multiple server-side platforms too, incl. some forks, so if mastodon.social is not for you – look around for better lighter alternatives (as well for self-hosting)
start around here: https://github.com/emilebosch/awesome-fediverse#applications
honestly, if github and HN suffice for all your social needs, you probably dont need anything else.
microblogging is not for everyone. but for others, since twitter is just no longer viable, people have been migrating to something that can't be just bought out by yet another rich asshole. plus privacy, extended control over your own data, and all that other nerd shit no one cares about.