The tricky part is that a truck is an incredibly expensive piece of equipment, and it needs a lot of maintenance.

Professional truckers drive, yes.

But they also inspect the inside and outside of the truck before and after each trip. Many of them deter theft and vandalism by often sleeping in the truck. Many of them can fix blown tire or a failed spark plug it more without outside assistance.

It'll be lovely not to have to do the actual driving, but owners who think that's the only skill that a professional trucker brings are in for a nasty shock if they immediately swap to untrained staff.

Once the trucks can drive themselves, a lot of the rest of what a trucker does can probably be done by fewer people, with the right coordination, resources and planning. But that's going to take a lot of effort, and it's going to have to be effort from actual truckers who know that they're doing.

Source: I automate other people's jobs, for a living. It's a long slow process, and there's invariably parts of their job that simply cannot be replaced by current technology.

I've seen executives conclude "I don't need anyone with XYZ skill set anymore, because the computer is magic", and then get fired a year later. The ones who listen to me avoided this, but I'm just a nerd, not a savvy synergistic business man. So what do I know?