Like many, my home and office internet comes from one of the leading cable companies, aka as a MSO. Over the past decade the cable giants in the USA have rolled out public hotspots, and also embedded their own "Wi-Fi" roaming capabilities so anyone who is a subscriber can easily log onto the "public" or a even a neighbors home network.
Unfortunately, logging on, surfing the web and basic email use is about all the "access" is really good for. Sure, you may be able to stream some content, but as a customer you should be able to receive what you signed up for at home given the authentication ties back to your own account. Instead you get speeds that are lower, slower and services that don't work.
VoIP is one of them. Since most VoIP providers use UDP, and since UDP is blocked, or TLS and TLS is blocked by firewalls, and those firewalls are turned on by default in most, if not all cable internet routers, calls don't get through. WebRTC often doesn't fare much better, as the ports that WebRTC uses are often viewed as suspect by the cable operators packet sniffing technology.
In reality, authentication technology has become rather advanced since the cable guys started to deploy WiFi and with the ability to manage the bandwidth to an access point now all cloud based, and cloud smart, the cable operators should let someone log on to the network anywhere they are, and use the bandwidth they are already paying for, wherever they may be.
Years ago Boingo would track your connectivity as you accessed hotspots they powered. Often they would log you off after three hours of connected status, and have you log back in. That was more than ten years ago, so if they could do something as routine as that then, the cable ops should be able to do more sophisticated tricks today. With 5G looming, connectivity remains king and being able to stay connected is paramount to those who rely on the internet to stay in touch, hold conference calls, make and receive calls and more.
The time has come for what's possible to become what's implemented.