I like this in theory, but in practice it is very useful to have a universal way to contact people that doesn't depend on both parties having the same proprietary[0] app installed.
If I give someone my phone number (or email address, for that matter), I know they will be able to contact me without any more coordination required. That has a lot of value to me. If we eliminate phone numbers entirely (and thus SMS, MMS, and telco-mediated voice calling), we lose that ability.
I do think that, in the future (perhaps not in our lifetimes) we'll do away with phone numbers, but only after there is another universal way to contact via messaging or voice that involves only sharing some sort of identifier, without any other setup required.
[0] Yes, Signal is open source, but since they refuse to allow people to use modified clients, or build support for federation, they are a proprietary, closed system, just like WhatsApp or Telegram. It's just we can have more confidence in the privacy of our communications on Signal due to its open source nature.
If I give someone my phone number (or email address, for that matter), I know they will be able to contact me without any more coordination required. That has a lot of value to me. If we eliminate phone numbers entirely (and thus SMS, MMS, and telco-mediated voice calling), we lose that ability.
I do think that, in the future (perhaps not in our lifetimes) we'll do away with phone numbers, but only after there is another universal way to contact via messaging or voice that involves only sharing some sort of identifier, without any other setup required.
[0] Yes, Signal is open source, but since they refuse to allow people to use modified clients, or build support for federation, they are a proprietary, closed system, just like WhatsApp or Telegram. It's just we can have more confidence in the privacy of our communications on Signal due to its open source nature.