These introductory five (four, really) episodes of Seinfeld are quite a mixed bag--and not all that great, in all honesty. Rating-wise, I'd give the bunch 4/10 stars (this coming from a reviewer watching the show for the first time in 2022).
The "pilot" episode--aired in 1989, a year before the show actually got rolling on NBC--is more a triviality than anything. Besides the very "bare bones", it isn't all that indicative of what the show would become in the summer of '90 or beyond.
The other four episodes? The characters of Jerry (Jerry Seinfeld), Elaine (Julia Louis-Dreyfuss), George (Jason Alexander), and Kramer (Michael Richards) are certainly present and being established. The same can be said for Larry David's (show creator) observational humor. But this is a show that relies on character quirks and longform familiarity and such things don't happen overnight. From snippets of reruns and here-say, I know that the core characters--and many more--become iconic later on down the show's road--but it hasn't happened as of yet in this batch.
Basically everything I read about Seinfeld cautions that the first mini-season is the "worst"--least funny, least quirky, and least-established (obviously). I very much hope this is the case, as over this short stretch the show--while not an atrocity--simply isn't all that funny or endearing.