> Aren’t roads necessary from a “last mile” perspective for like, all sorts of things a functioning country needs?

Yup, absolutely! But at least where I've worked on road design, the number of lanes on a local road is governed pretty much solely by the number of cars (trucks just have a larger impact on asphalt structure choices and, balance with the impacts of freeze-thaw, resurfacing schedule).

But this is about longer distance travel - trains generally being used for intercity travel vs highways. Even still, I don't argue against road subsidization, but rather in favour of more train subsidization.