I'm told hikers have completed thru hikes with a single polycro ground cloth. Except for the thorny desert polycro ground cloths reportedly hold up very well. I'm experimenting with some for a light tarp in good weather.
I'm sure some have. Some folks have also hiked the entire trail with a cuben fiber pack, but I've seen the abrasion on mine and don't think I would accept that in a ground cloth.