Re: What I'd like to see
"The last thing I want is to try to reach someone who then has to have an account with some service"
How do you envisage finding that someone if they don't have an account with some service? They, and, come to that, you, would need to have a unique ID. Who manages IDs in order to ensure uniqueness? You then need the system to be able to contact them. How do you manage that without using some form of service mapping the ID to some communications address?
Example: "I want it to be as easy as group chats or group calls on my phone"
The telecoms companies provide the ID, and map ID to the handset and locate the handset in the mobile network.