I think part of the argument here is that many “truck drivers” essentially aren’t, because of how job classification systems work. They’re doing jobs where most of their time doesn’t involve driving a truck.
The problem with this argument is, in part, as you say - certain jobs will need to be done by somebody, but it can be done by a smaller pool of workers who aren’t drivers. The other is something that we saw in the last recession - certain workers had bits of their jobs automated, but the jobs still went away, entirely. Either because the remaining bits of the job just got dumped on the remaining workers (i.e. their job descriptions expanded to take on new, extra work at no extra pay) or because the remaining bits of work could be automated by some other process(es).
So I wonder how much they’re underestimating job loss, assuming that if some part can’t be automated, the whole thing won’t be. That may be true in some cases, though - if a delivery driver’s main job involved removing the load at the drop-off point, and that part of the job can’t be automated (or done by someone else), then that job could be safe as a whole, even if the “driver” is essentially a passenger for the driving bit. (On the other hand, the “driver” could end up getting less pay for the new version of their job, too, given its reduced workload…)
