Protection

It may or may not give as good protection, but, when the wind makes it flap it can abrade the outside of your RV.

I used one for 13 years on our last rv and it looked like new when I traded it in. We get light to moderate wind here but rarely anything damaging.
FWIW, I keep our new rig under a carport and the old cover actually kept the rv cleaner over the winter.

While a roof is easier than a cover a cover does a good job.
There are places in this country I’d say a cover wouldn’t last long and could also scuff from flapping in the wind, but Indiana isnt one of those places unless there’s a tornaado or may be it’s stored on top of a big hill with no trees.
The 2 winters I’ve used a cover, the rv didn’t even need washed in the spring.

Unless the camper is not very valuable at all, I wouldn’t store mine outside in the off season without a cover.
And sun does as much or more damage than rain and snow.