It got sorted into the wrong bin, which went into an entirely different truck.
I've been saying for years that USPS, UPS, Fedex, etc should eliminate their stop by stop tracking visibility and change it to "Your package was picked up" and then say "Your package is on schedule and expected to be delivered on XX/XX/XXXX" or "We apologize but your package is delayed. We'll update the delivery as soon as possible." These aren't dedicated, door-to-door delivery services.
If I send a package to my Mom, who lives 85 miles north of me, her packages actually go 165 miles north (past her), then back south ~80 miles to her. Does it look silly on a map ? Sure. Does it make 100% sense from the shipper's side of things ? Guarantee you it does.