Our tents and rainflies are stored in relatively large breathable bags. I don't fold tents, just stuff them loosely in the bags. I have 4 tents with the oldest being 20+ years old. I'm still using a section cut out of the rainfly of a tent I had in the 70's for a footprint for one of our tents. The coating on that remnant is still serviceable. Two of our 4 season tents have been used extensively for mountaineering, and have experienced a lot of pretty hard use. Storing them loosely stuffed in large breathable bags did not seem to do them any harm.
I just make sure they are clean and dry when I put them in the bag.
This tent is over 20 years old. It has been relegated to "car camping" because the pole sleeves have worn through in a few spots due to wear and tear, However, the coating on the rainfly is still in good shape.
We also have several Therm-a-Rest pads in various configurations. They are stored, partially inflated, standing up against the wall in the corner of our gear storage room. A couple of them are probably 25 years old. I think this is better for them than rolling them up for storage.