How is it a worse experience? It's ridiculously simple: The app sends a public key to the person you're talking to. The end user doesn't even need to notice it. What am I missing here?
I used to help a nonprofit with their facebook account, made it a real pain in the ass for everyone involved.
Of course facebook has no customer service and their slop docs were of no use.
It's fine for the use case they're meant for. Unlike Instagram, they had these usability limitations from the start, and they delegated auth completely to the phone providers.