Your bet is right, but it's based on a misunderstanding. Those are not real subsidies, those are tax exemption on farmers, fishermen, trucker and traveling nurses.
And airplanes. They also pay no fuel tax, as far as I'm aware. Or at least it's rare; it requires bilateral agreements to tax fuel.
And airplanes. They also pay no fuel tax, as far as I'm aware. Or at least it's rare; it requires bilateral agreements to tax fuel.