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.
“I Love Lucy” pretty much created the television universe as we know it. Now it may be dated but it doesn’t get much more influential than that. The same could be said for Birth of a Nation for the motion picture industry. Very dated now but there is no denying it laid the foundation for the major Hollywood studios.