It's sort of relative. If you have a 25 year credit history, then, no, 3 years isn't long. But if you are 22 years old and only have a 4 year credit history, then, yes, 3 years matters. In general, I'd vote for closing them if they really aren't doing anything for you.

I'm also of the opinion that Ch@se doesn't really care about MS too much. A few years ago they were happy to sell us their own VGC for no fee, with their own credit cards. Does anyone else remember those good old days? (I know, times have changed.)

BUT, if suddenly you're maxing out the $15k credit limit on 4 cards at once, that's probably going to get their attention.