Seems like it would be much easier to just hire a few extra people for each shift so everyone isn’t pushed to a burnout limit all of the time.
I do most of my groceries through Ocado, and their warehouse operations are almost fully automated[0], but then on the delivery front I can only assume they staff much more generously than amazon, because their delivery drivers are always much more relaxed than Amazon drivers, they're quite happy to have a chat while unpacking, and often call saying they're running early and ask whether it's ok to arrive before the delivery window.
The warehouse still needs lots of staff but less than a supermarket
I'm unsure if I personally am in need of prepackaging an order living in a city. Having 5 minutes on foot to the next market I like to see it as a break. But different lives, different needs.
As for deliveries, London isn't super car-friendly, so I only do shopping in person when I'm comfortable carrying the shopping home. As you say, different lives... :)
From the little I’ve seen I’d rather work there than a meat processing plant I’ve been inside of, and I’m guessing the pay is comparable. Those types of jobs suck, and there’s no way to make them not.