Even crappy home routers can port-fwd, the real barrier here is the ubiquitous (in America at least) prohibition on "hosting a server" on a residential internet connection.
You think everyone serving their own services from their residential networks is the solution? Have you thought through the security implications of that?
I can just imagine the technical support hours I'd have to log when my dad calls me up because his email server is down or his home storage is encrypted by ransomware.
Of course I have, that's why I run pfSense, a separate host for my DMZ, a reverse proxy, an IPS, and don't have DNS pointing to it (marginal benefit, but I don't need it so it's off).
I'm not arguing that people should do this, I'm arguing that the "NAT is a barrier" position espoused by the "evil ISPs are trying to keep us down, man" camp is incorrect.
NAT being necessary because of IPv4 has lead to this really useful low barrier to self-hosting. People who grok security and want to do it can, but it's just arcane enough that lots of people who shouldn't self-host are scared off and go to AWS.
A messaging app doesn't have to require port forwarding, it can use a central server to broker the connection between endpoints. In that scenario, the "server" is on the internet, not the residential connection, but data comes from the endpoints.
