Truly?
My mom always has a grocery bag tied to the outside of her pack and I'M the one who has to do all the bending to pick up the trash on the trail. Honestly though, we might find a water bottle or the top of a gel pack on the trail sometimes, (on the PCT we find, but don't pick up, poo tickets. Thank you whoever introduced that term!) but a majority of the trash is located closer to roads. We don't even get a bagful on a typical 10 mile hike, but would probably get several bags full if we hiked 10 miles along the road.