"Oh your boss threatening to fire you is 'like communism'"
"I listen to guys who are forced to work on weekends say that it's like communism"
"Is your giant multinational company communist?"
[audience laughs]
"Does your CEO have a portrait of Stalin in his office? Do your kids read Karl Marx in school"
[laughter]
"I mean, really, are we [pause] not living in a capitalist country?"
"People keep pointing out child poverty here and say it's like North Korea. Have you been to the DPRK? Can you really say that the stuff you see daily is going on in the competing social system you know nothing about?"
[♫ da da da da ♫]
Honestly the brains behind the most of the comedy in Seinfeld is Larry David, who either wrote about his own personal experiences getting into absurd situations he finds himself in, as an extremely wealthy and privileged guy that I'm 99% certain is an undiagnosed autistic - hence the constant social faux pas, or he's exaggerating those experiences and writing about what he would do in hypothetical situations and the fallout from his inevitable gaffes.
If you've ever watched Curb Your Enthusiasm, starring David himself, it's like a more mature version of Seinfeld except that he's a combination of the Seinfeld and George characters.