@soop The phone number requirement exists to prevent spam. You don't have to share your number with your contacts though, that's why user names exist.

@Andromxda @soop the addition of usernames is the thing that makes signal viable for use among people who aren't my immediate friends and family, although I still use it primarily for that purpose. An architecture like Matrix or xmpp where it's username@domain and you just sign up for it like any old thing is still preferable although doing that will also controlling for spam is a task needing a solution