This is a question I had been asking for several years until I came across Twtxt (the spec/format originally created by Felix, @buckket, read about it at https://twtxt.readthedocs.org) -- When I came across it I saw a bit more potential so I created (what is effectively) a multi-user client also called Twtxt over at https://twtxt.net (launched in Aug 2020). Since then we've also created a Mobile App (Goryon) available in the App Store (iOS) and Play Store (Android), we also offer free (at this time) hosting of pods (individual instances) at https://twt.social/ -- Today we have a dozen pods/instances and some ~300 users. My own pod (twtxt.net) sees around ~4M hits/month :O