One of the true gifts of Seinfeld is that almost universally people found their real lives so matched the show in one little phrase or another...I'm a huge fan and I constantly have things happen in my life that I think, hey it's just like episode such and such...truly the gift that keeps on giving...count me as so thankful that they gave us 9 years.
The problem is there are very few Larry Davids and Jerry Seinfelds. Most showrunners are not of their caliber. If networks ran shows for a year before they canned it for low ratings, they'd go broke.