Lots of goods are shipped via train. It's very cheap. But it is slower, and you still need trucks for last mile delivery... Or in lots of cases, last 100 miles delivery.
Trucks are the only option when your local rail operator shuts down or doesn't have the capacity to service your business. This chronic underinvestment in vital infrastructure is hurting the economies of smaller towns, making any business that needs cheap transport to thrive less competitive.
If all we needed were short-haul last mile deliveries we'd eliminate millions of truck miles per year (huge economic and environmental win), move those trucks to green propulsion and it's even better.
This can't happen with how the infrastructure looks today though. Which is why I question the money spent on self-driving instead of fixing the whole transport sector. It's bailing water faster in a sinking boat while ignoring the gaping hole in the bottom.