A point often neglected in such comparisons (regardless of the actual conclusion), is that paper towels are useful for more than just drying hands. What if I'm at a restaurant and I wish to wipe my trousers because I spilt a sauce on them? Or what if I just walked in from a walk and I want to wash and wipe my face? Or what if I just ate something oily and I wish to wipe that away (oil doesn't evaporate noticeably and will stick around until wiped away).