Almost 25% of Americans are rural as well… bikes and public transportation are never going to work for them. In fact, cars don’t always work for rural folks - a lot of them benefit from (if not outright need) trucks.
A large, spread-out community? Perhaps not so much.
But a small town where 80% of the people commute to surrounding cities? That'd be a great case for 1 or more commuter train, depending on direction and demand.
But even then if the train is hourly you need to be organized. No going out ona whim.
This is despite urbanization being lower then than it is now[1]. Some of that is because Americans became wealthier and demanded private alternatives to mass transit, but a lot of it is because we chose, as policy, to deprioritize effective mass transit.
[1]: https://en.wikipedia.org/wiki/Urbanization_in_the_United_Sta...
Trucks become more practical in rural areas because of the lack of amenities that exist around cities and towns.