UPS drivers are all about timing. They know precisely what they can carry, and what amount of time it will take them to manage the packages, with or without the awesome heavy-duty UPS convertible hand truck.

Partly because they are trained and know their craft - but mostly because they are correctly paid, and so they are almost always long-term workers with learned expertise at driving and delivering.

(As opposed to the Atlantic writer, who did the job for a day, didn't know how to do it correctly, found it difficult, and whined about it. That's not actually telling us much of anything, when you think about it.)