Just because Seinfeld ended 17 years ago doesn't mean you can't watch new episodes.
Seinfeld is remembered as one of the greatest sitcoms of all time. Unfortunately, the modern generation will probably have no understanding of Seinfeld unless they watch TBS, and even if they do that they probably won't understand most of the references. I mean, there is an episode in which George Costanza tries to rent a VHS of Breakfast at Tiffany's. Doesn't get much more '90s than that.