I can email mike@somedomain.com but I can't "call" or "text" mike@somedomain.com . You can kinda sorta see this now with imessage / facetime, but that's not consistent and implemented in a standard protocol.

So phone numbers could have become more semantic. Instead we have arbitrary phone numbers and wrap meaning around them.

I guess it’s been so long that I needed to find and type out a phone number that I don’t think about it any more.