Back when I still had ISPs that provided the modem + router, every single issue I think I ever had fell into one of two categories: a modem and/or router power cycle fixed it, or it was a broader network issue that had nothing to do with me or my particular internet situation (this is omitting the most common third issue: terrible customer service problems, but that's a separate thing)
Also I could save them a bunch of money getting rid of services they don't use, like moving their landlines to VOIP.
If you want a landline to call emergency services, I'd expect a real landline will have higher uptime than one that depends on your router.For example, if you subscribe to Verizon FiOS voice, the technician will disconnect your copper phone lines and connect them to VoIP termination on your ONT.
That's what I did for pocket as a kid in high school (in the mid-2000s).
You call an electrician or a handyman or somebody and tell them you have some low voltage work.
The ISP provides a cable box and modem to most homes in the same way that the electric company sticks a meter on your wall.
In the US, most do. This is a standard part of "in home installation" when first subscribing to service for all of the major providers in the US.
Example: https://forums.xfinity.com/conversations/customer-service/sc...
Also, as the other commenter pointed out, ISPs don't terminate their service at the edge of your premises. Basically all of them today will connect one of your devices to confirm installation.
In San Jose, if you see evidence that your house's main drain has backed up and you have a cleanout within 5' of the sidewalk, you're better off calling the city first before calling a plumber -- the sewer department will snake the "lateral" pipe between the cleanout and the main sewer line under the street for free.
The one time we used this the response time was very quick (in line with the 30 minute response time they cite on their website).