A lot of plans do. Especially with the major telecom networks like ATT and Verizon.
Recently had a smaller company come in and install fiber. $85/mo for Gigabit service with no data cap. That’s pretty good compared to what I was paying. ATT only offered 500Mb/s and that was over $110 a month with a data cap, I want to say 800GB.
Do not get reliable enough cell coverage for one of those mobile routers. But they aren’t any cheaper here since those are owned by the major telecoms.
Bystander effect