alt Hacker NewsThe best feature of FB is reach. You can't replicate that without a global social media platform. So don't. Just build local communities that thrive _despite_ the fact they are started on FB. More in-person social interaction might upend FB and social media, but we currently play this game so these are the rules we must follow.
It's reach and UX.
Normies can use it.
People who were in early days of Internet remember who bad email mailing lists were for organising anything. Mailing list, Usenet, IRC, are all now dead because no one could invest to UX in these early open protocols.
In theory you can reach all users using a mailing list but oh boy, good luck with that one, unless all of your peers are kernel developers.