First of I’m not all that tech sevvy in that regard so maybe there are technical limitations.
But besides that, in times were online privacy is almost non existing anymore it seems like it would be used by many people.
What I’m thinking of goes along the lines of:
Send message – message goes to server for forwarding – message goes to target – all information (IPs, message content, message target, etc.) get deleted from the server as soon as it has been delivered.
It might not be as secure as I think it is in my head but it seems simple in theory.