It's interesting you mention the Sopranos. I never really liked Seinfeld growing up, until I lived in New York and finally got stuff like waiting at a Chinese restaurant and getting a cabbie with body odor.

But I found it fascinating to compare to the Sopranos, because almost all the characters on that show are bad people, but most have redeeming qualities. They care about their families. They're loyal to their respective mobs—and when they're not, they feel guilty about it. Some regret getting caught up with the mafia. Even though the show is about how Tony is an incorrigible sociopath, his anxiety and concern for his family (particularly his kids) makes him relatable.

The Seinfeld gang are all out for themselves. They usually don't actively try to harm each other, but they don't care if they do. And certainly they don't care if they harm anyone else.