Somebody has to pay for the infrastructure. You can either have a very loose federation of a lot of individuals running their own infrastructure like in the early Internet on one end of the spectrum or a couple of big companies that essentially run everything like we have now with Google and Meta. But someone has to run it. If you rely on a single company to stand up everyone's instance of the application, then you're right back where we are right now. And how do you manage all of the configuration data for all of the users? There are a lot of practicalities here that I worry you don't appreciate when you say "It's a protocol that anyone can implement." Well, so is PSTN. It just so happens that you need a certain amount of infrastructure to implement it, which is true of everything, even email. I'm not convinced that a new protocol gets us anywhere because it doesn't solve the underlying very human tendency to want to pay someone to deal with all the unsightly stuff so you can get on with your life, which is incidentally also the problem we have with email vis a vis Google.
> You can either have a very loose federation of a lot of individuals running their own infrastructure like in the early Internet on one end of the spectrum or a couple of big companies that essentially run everything like we have now with Google and Meta.
Or you could have thousands of medium-sized companies that each operate nodes that interoperate with each other even though none of them is the size of Google or Meta, and users could choose one based on whether they want to see ads or pay a few bucks a year, or run their own if they're into that sort of thing.
> It just so happens that you need a certain amount of infrastructure to implement it, which is true of everything, even email.
The infrastructure you need for email is any functioning general purpose computer, including ones you can find in the trash, and a domain name, which you can also get for free if you really want to and in practice costs around $15/year to do it properly. Anyone with the inclination can do this and many solitary individuals actually do.
The infrastructure you would need for this thing would be even less, because the premise is that you already have an email address/provider, so all you'd really need is the ability to map a port so you can make a direct connection to the other endpoint -- or IPv6.
Whereas the infrastructure you need to participate in the PSTN... I think you're required to be a CLEC to even have a block of numbers assigned. If all you had to do was install Asterisk on the trash PC it would be something else entirely, but the telcos do a lot of regulatory gatekeeping, which is another reason the legacy phone network should be decommissioned and replaced by a modern IETF protocol.
