Alright show, funny but flawed
As a kid, I loved Seinfeld, it was my favorite TV show. However looking back on it I realize the racism, homophobia, and general ignorance of this show. Unlike shows like Friends, Seinfeld is very self aware and the absence of black people is sometimes the main joke of an episode. If you are young enough, most of the stuff will go over your head, and many episodes are really funny and clever, but showing this to an impressionable child could mean them becoming a casual bad person.
Some examples: Burning of the Puerto Rican flag, accidental blackface, etc.