The storage lot we store our 5th wheel in has over 400 spaces. I will see new RVs come to be stored, the owner will put the cover on and within a year no more cover on the RV. Either the cover ends up shredding due to weather or the owner finds it's too much trouble and dangerous to put on and take off the cover. Of the 350 plus rvs stored in the lot only a few have covers.
Ours is 21 years old and never covered. When washed and waxed is looks brand new.