The basic ability to send messages to your friends in real-time is the problem. I don't think that is the problem. Sending messages to your friends still has a

The basic ability to send messages to your friends in real-time is the problem. I don't think that is the problem. Sending messages to your friends still has a social contract, and abusing that privilege has repercussions. Sending messages anonymously to unknown people is much more of a problem (e.g. robocalling).