I took it more to mean Charles Shultz agrees with me that no rock artist puts out their best work after 30 so Dylan's peak was already behind him.
But that would be incorrect as Blood on the Tracks was recorded in 1974...
Great artists can stretch their peak
Bob Dylan was still bringing the songs for decades after turning 30
I think the problem is it gets harder to dress them up or produce them
And of course the context within which the songs are delivered changes
What Dylan lost wasn’t the ability to write great songs as much as the ability to connect with his surrounding context...with the times..to remain socially relevant.. from 1962-1966 the guy was just amazing reflecting back to society what was happening in ways people could process.. he had like an antenna and the songs just came to him from the world... I think he has said this himself.. after the accident if it happened or the break or getting married he became more insular.. the songs on BOTT come from within him..a completely different approach
That ability to reflect the context of the times through song probably does have a shelf life of about 30