I do notice my interest in gaming several (1% or less) cards is starting to wane. Sometimes juggling cards makes for fun mental exercise. Then again, sometimes I'd rather not bother. If it ever gets super annoying, I suppose I'll cancel whatever cards I don't have a use for. I'm good for now though. For the most part, I enjoy it.
For me it depends. Some days I honestly miss the times when I didn't know much about this stuff, just used my Discover for everything, and went on with things. I've found that at my fairly low spend level, juggling a bunch of cards doesn't really give me much in the way of substantial benefit. I hope to end up with maybe 3 or 4 core cards and call it a day. If people don't mind juggling, it can pay off in certain situations. It's just for me the effort vs benefit is questionable at times.