Don't watch/follow any of them, but I'm forced to sit through them unless I can find something more fun to do like clean a toilet.
I do think they have had an effect on society though.
Most "reality" shows are elaborate game shows when you get down to it. There are some other types granted, like Duck Dynasty, and Pawn Stars, but they seem less "reality" and more "reality based sitcom".
Liked Flying Wild Alaska. I enjoy Bear Grylis shows, but now its just a venue for his product placement. All are edited for maximum enjoyment, thus the reality is gone.
The only one I ever cared for was Top Shot. Now that it is off the air, there is no reality TV that I can stand to watch. I haven't ever seen the Street Outlaws show... I could maybe enjoy something like that, as long as it is less than 90% **** talking, **** stirring, and fake drama, and over 10% cars, racing, discussing builds, etc. I don't have much faith in that being the case though.
Impact on society? There was low-intelligence entertainment before reality TV, and I'm sure it will find different outlets in the future. But seeing how the main premise of reality TV seems to be stretching maybe 10 minutes of substantive footage into a 45 minute TV slot, with an artful mix of filler taking up the rest, I wonder if it provides a sort of countervailing effect to the impatient, "gotta have it now, gotta be stimulated all the time" millennial culture, and causes those who view it to have some sort of capacity for patience and boredom. A more likely theory is that most people use it as something that doesn't require much mental engagement that can be on in the background while they surf the web and do social media.