While it is possible that orders are up, it may be that the delivery companies including Amazon didn't increase their temporary hiring this season like they have done in the past.

Anything is possible, I suppose, but I’m not gonna think that’s it. Since Amazon opened two distribution centers here, each about 15 miles from me (and 30 from each other) I have seen more Amazon vans running up and down the street than ever.

More than that, a few weeks ago I had to rent a truck to pull our boat from the river for the winter, and while at the rental place two guys were trying to rent a work van. “Don’t have any, won’t have any for 6 months” the guy at the counter said. Since Amazon opened up delivery to independent contractors they’re fresh out and have a months-long waiting list. (The Enterprising, uh, Enterprise employee tried to talk them into a large box truck, but they weren’t having it. There weren’t any work vans up the street at Budget either.)

Additionally we are suddenly being served by a plethora of other “last mile” deliverers. In addition to the usual suspects (USPS, UPS, FedEx) there is now Amazon (of course) and a bunch of new delivery services coming online:
explodingtopics.com - Delivery startups
And they’re all showing explosive growth. Not to mention DoorDash, UberEats, and similar.

No, I think the logjam is upstream: too little inventory coming too slowly off the boats and trains before getting to the warehouses. Just my guess, of course, I have no insight into this entire part of the industry.