Yea, actually, he does. Just as few people can do the type of thinking required of his job as can do the physical work of driving. I've done both jobs, and, I've been a mason tender working construction, which is a damn sight more physically demanding than driving. They're different.
Driving demands physical energy but when you're on a bid route, you can almost mentally check out all day. Knowing your air stops, floor stops, and next 5, next on call, becomes a routine. You fight boredom by running songs in your head, chat up receptionists for a few seconds, etc. Everyone here wants to talk about delivering a Bowflex up 5 flights but that's the exception not the rule. The rule for many is a paper route in the suburbs in good weather. And at the end of the day, you walk home without a single work worry. More packages will be there tomorrow, but I'm done today and walking out feels GREAT.
Try figuring out novel problems for an entire day. Try being on a call for 15 hours overnight working through an issue when Australia customs doesn't have the data they expect. No methods, no standard way of doing things, no routine, no way to just tell your on-car supervisor "I don't know what to do here, tell me what you want because it's not my problem". You're completely ignorant of this kind of work, based on that statement. You'll walk out of your office completely drained, without lifting a finger.