I have large rubber gaskets that do the same thing with my slides. I don't get water or wind inside my rig. I also see that if this is any kind of fabric, then I would worry about things falling on the roof, puncturing the fabric, then what.
Imagine this.... you go on a trip and you are setup. It rains the whole time you are there and now you gotta leave. Isn't this why you have an RV so you can live through this stuff (it's happened to me)? The slides go in with this wetness and you'll now have to air out the rig somehow and somewhere so the material dries out COMPLETELY or you're gonna have destructive mildew and odor problems. Some people do not have the luxury of time or storage to do this.
This is also warranted for only two years. That doesn't sound like very long when you figure the rubber on the RV lasts many years longer than that.
When my rubber gaskets wear out, I'll be able to replace them easily since the rubber is only at the RV edges, or if I have it done the labor will be less expensive with the existing rubber. This looks like it must be measured and installed correctly especially around windows.
This might work for some people who want to accent their slides but there are too many downsides so it wouldn't work for me.
I just recently had them installed on my Rv and I have had my new Rv now for three years. It came with a one year warranty on the rv. In the first year when it would rain it leaked around the slide out. We took it in for service and they adjusted the box and replaced the wipe seals around the slide out. It seemed to fix it. So several months later we went camping and we had a hard rain and the carpet around the slide out was wet. We took it back to the shop and this time the floor had a soft spot from the water, we were out of warranty by this point but we had an extended warranty. They said it was not covered because of seals not being part of the warranty terms. This has now cost me a lot on money to have it repaired. While doing some research I found out that the slide out boot was water proof and mold resistant. So when I saw the slide out boot I knew right away I needed them on my rv. It has given me the piece of mind that I can keep my money in my pocket and when it rains we don’t have to keep looking at the slide out to see if it is leaking and enjoy our trip.