They're not unheard of in cities. Hotels and shopping malls have them. Some residential ISPs will also broadcast a public access point using a slice of each customer's bandwidth allocation...
When I had Comcast internet, I could get on those, but it required a network profile to actually connect to the internet. That said, I wouldn’t put it past TV makers and Comcast to collude on using this to allow backdoor network exfiltration.
They all have captive portal for regulatory reasons though.
Another reason not to use ISP hardware. That's on top of a well-known backdoor (https://en.wikipedia.org/wiki/TR-069).