How are things going with the unified instant messaging protocol (similar to email)?

Question

Communication protocols

For example, there is an email protocol. It is convenient because the interlocutors can send messages without being tied to one company (with gmail, the letter will successfully reach mail.ru, from yandex to gmail, and so on). Thus, a user can only interact with one email client (application).
With messengers, everything is more complicated. People prefer different messengers, but it is impossible to send a message, for example, from VK to telegram or from instagram to whatsapp. Why is there no single protocol, like with email?
Perhaps there have already been attempts to do this? How are things going with this? Why hasn't the email protocol been upgraded to messenger capabilities? Or updated, but no one wants to implement this in social networks or existing instant messengers?

Answer 1

there is an email protocol

There is no such protocol.
There was such, XMPP was called. Here the problem is not in the protocol, rather, but in the servers where user accounts are stored.
So XMPP.
He died.
"Why don't they put racing engines on trucks?". Because there are other tasks.

Answer 2

Have you heard of Jabber?

Answer 3

For example, there is an email protocol

No, there is no such protocol :) If I'm still mistaken, name the RFC where it is described :)
Because no one wants it :)
Because:
- there is no email protocol
- even if there was one, nobody would need it.

Answer 4

The short answer is because it is not profitable for large companies at the moment (if you do not delve into the problems of capitalism in principle). And so, there are attempts, for example, Delta Chat over e-mail, see https://habr.com/en/post/442266/