The friction it removes: needing three things at once, and never having them in the same place.
The clip lives in the car. The bags are in a drawer by the door. So you improvise — a carrier bag from the kitchen, doubled up and hoping — or you say you'll get it on the way back, and then don't.
This carries its own roll. Fold it shut, leave it in the door pocket; unfold, clip a bag on, pick up. One object, so the bag is always where the clip is.
What we gave up: PE — light because it's light. It won't grip on grass or gravel.
