Where do you live? Are tractors not taxed as motor vehicles in your country?
If we tax at the state level like motor vehicles, what happens when AI living in a Texas datacenter replaces 1 million jobs in Florida? The people are in Florida, but the money goes to Texas.
Nope.
They even get to use fuel that has less taxes on it since they don't drive on public roads.
Normally not unless they travel on public roads. If it's just used for farming it doesn't have to be registered.