Weirdly enough, services like WhatsApp, Signal, or Telegram are more portable. Because the identifier is not owned by the service but is provided by s.o. else.

Weirdly enough, services like WhatsApp, Signal, or Telegram are more portable. Because the identifier is not owned by the service but is provided by s.o. else. It is essentially a decentralised social graph in the address book of your phone. I'm aware of the caveats though.