I hated Seinfeld when it aired but I've mostly come around to it. It basically pioneered the genre of shallow insecure narcissists clashing with each other and their surroundings, at least on a big mainstream level. At the time I think it was kind of an anomaly when many sitcoms weren't like that at all. It's basically, what if instead of having one occasionally neurotic character, all of them were neurotic all of the time?

It has inspirated truckloads of later shows. Some of them took the concept much further and made the characters far more passive-aggressive or even outright hostile to each other (Strangers with Candy, It's Always Sunny in Philadelphia). And I would mostly say they are funnier for it.

Jerry Seinfeld himself is a piece of shit genocide promoter though, so I wouldn't advocate watching his show unless it's free.