I see your point, but the examples I notice across fields including writing, demonstrate a strong preference towards [relative] youth.
- Neal Stephenson (My favorite fiction writer) published his first book in his early 30s
- Hemingway published great works in his early 20s
- Almost all of the most notable scientific breakthroughs in the 20th century were from individuals in their 20s. Schrodinger was the Old Man at 37!
- Most famous musicans started releasing their first, and often best, albums in their early 20s-early 30s. When they tour into old age, they're mostly playing their hits of youth.
I think, perhaps, the trend is even more pronounced in scientists than writers. Skews early-20s.
You can find exceptions, but the exceptions are often not that old, and in the anecdotes I think of (Favorite authors, writers, musicians etc), it's hard not to notice the trend of youth. I want to find this trend to be untrue because it can be depressing, but can't. (This is at the core of the article)