To the OP - obviously opinions vary. I see you are in Nevada which presents the same harsh elements during the summer as I see here in AZ. Here are my thoughts FWIW(copied from a post I made in a similar thread.)
We cover ours as we can't build a permanent structure at our house. Yes it is a pain but I think it is totally worth it. Here is what I can tell you based solely on my experience here in Arizona:
I have yet to see an RV left completely exposed, long term to our intense sun that had a nice looking finish. Keep in mind, we have 5 months of 100+ degree days. Many of those 110+.
I have seen lot after lot of RV's in storage out here and almost everyone of them has faded or oxidized if they have been there long term. This is the case with full body paint(often faded and/or covered with paint checking from the heat) and also non-full-body paint coaches. Decals don't stand a chance!
We had our last coach covered for 5 years without any negative effects from the cover on the paint. Yes we have dust storms and monsoons but it never damaged our coach.
Believe me, I would LOVE covered storage but that would have to be offsite for us and we like having the coach at home.