Jerry Seinfeld, Steve Martin and Quentin Tarantino show the psychological power of walking away at the top.
Loved the examples you've picked up. Reminds me of the term 'jumping the shark' which refers to that point in a show or a series of works where the quality starts going south. From your examples, you see that Modern Family, The Simpsons, South Park.
Peak-end rule is also interesting because of duration neglect. Because we're sort of averaging out the peak and the end points, we tend to ignore much of the rest. A terrible vacation that ended with a glorious day ziplining tends to be recorded in memory as a better trip than what it actually was in real-time, nudging us to do it again.
Jordan showed us both scenarios the retiring on top and the staying on too long.
I think the one people prefer is the first