It’s always been perplexing to me why XMPP never gained huge momentum. My phone (JMP) actually runs over XMPP. It works brilliantly, and can be paid for in Bitcoin. And you can even self-host your XMPP sever if you want to.

In my case, the XMPP client I use to make and receive calls on my phone runs on top of silent.link eSIM service, also paid for in Bitcoin.

It’s not perfect but it’s a pretty sweet setup. The only thing JMP sees is my anonymized IP address.