Seinfeld came after Hill Street. All In the Family was not a serialized story (ongoing plot where what happens in this episode effects the world the next episode will be told in). Prior to Hill Street serialization on TV pretty much only existed in soap operas, and even soap periodically “reset” back to the baseline so they were really episodic they just had “episodes” that last months.
While we are at it... I nominate BARNEY MILLER as a great cop show.. That was hilarious. And a great theme song!