As bob1029 said, making apps is easy especially now but getting friend groups to move is the real challenge so I think a column in the table should include a score for how easy it is to import Discord server history, chat history, invite friends and so on. I think there would have to be next to no friction or risks. If self hosted then backups would have to be encrypted and automated so that the servers can be treated as mostly ephemeral. Operating and maintaining Discord takes a rather large team so these open source alternatives would have to be able to show they have automated most tasks in a secure and fault tolerant manor that is hard to get wrong.