I'd guess we see tractors as the first step. They typically drive so slow the controller only needs to have stop button. If a farmer could simultaneously monit

I'd guess we see tractors as the first step. They typically drive so slow the controller only needs to have stop button. If a farmer could simultaneously monitor just 4 tractors, you could make tractors half the size while having twice the work done. This would double the number of sold tractors, which gives economy of scale. While also making assembly lines lot smaller and simplifying logistics. Trucks don't scale in similar fashion. Inter-modal containers are lot bigger than ploughs.