not op but signal has basically solved this. users are not just randomly accessible by anyone. they can share a long URL that contains an ID, or make a short username they like and pass around to people. and even then the recipient has to accept being contacted by each other user
AwesomeLowlander@sh.itjust.works 5 hours ago
At that point, you (well, not you per se) are basically suggesting to replace the telephone system with a Signal-esque system. Which would break a billion things in real life, for little to no gain.
WhyJiffie@sh.itjust.works 3 hours ago
any change would break a billion things in real life, so we could at least have a proper replacement.
the problem with signal here is that it’s centralized, probably couldn’t even handle the load besides other problems. but that’s solvable, like look at simplex which is similar