Why not just give up on the legacy telephone system? Decades ago we had dialup internet - a service entirely unrelated to the telephone system, built atop the

Why not just give up on the legacy telephone system? Decades ago we had dialup internet - a service entirely unrelated to the telephone system, built atop the existing telephone infrastructure. The US or EU or whoever could simply design a new service built atop that existing infrastructure. Telecom companies could double as Certificate Authorities for the new system, providing and signing certificates used to authenticate both sides of a call and encrypt traffic between them. It doesn't even have to be limited to calls. They could also support text or even arbitrary data. It could be a revolutionary new platform for instant communication, separate from the internet and backed by major nations across the world. And the best part is the infrastructure is already built! Or they could keep playing cat-and-mouse games with spammers for all of eternity.