A few years ago I actually traveled all around the US and worked remotely with a 4g unlimited data sim card and was pretty amazed at the coverage, only very few places was I left without coverage. I'm guessing it's even better now?
You should spend more time out west or midwest in places like: Nevada, Arizona, Colorado, Montana, Wyoming, Utah, Idaho, Nebraska, Missouri, Oklahoma, Washington, North Dakota, or head up to Alaska, etc.
There are a lot of places in and around the Appalachian and Blue Ridge mountains that have no service.
Note: I know a lot of rural ISPs serving these markets, or that have been trying to for decades - I know precisely when StarLink will work like crap or be great for the customer (given options at all).
A few years ago I actually traveled all around the US and worked remotely with a 4g unlimited data sim card and was pretty amazed at the coverage, only very few places was I left without coverage. I'm guessing it's even better now?