You also have to recheck your luggage at the first point of entry in USA/Canada - at least if you continue in a domestic flight. This is also time wasted, as yo

You also have to recheck your luggage at the first point of entry in USA/Canada - at least if you continue in a domestic flight. This is also time wasted, as you have to get through imigration, wait for your luggage, get your luggage, get through customs, check in your luggage (again), and go through security (again). OTOH if you are flying back to EU/Schengen Area, you'll get your passport checked at EU/Schengen Area point of entry, get through the sterile transit, and only pick up your luggage at your destination.