Those are all pre-modern people before the invention of vaccines and antibiotics and who had terrible health and suffered by now preventable childhood diseases. Their 35 is not our 35. Shakespeare, I believe, wrote about joint pain, aging, and losing his memory and mind at 35, which is not typical of a modern 35 year old. Substance abuse and artistry go hand in hand and a lot of these artists were addicts and drunks who badly damaged their brains. Many of them had mercury poisoning from medical treatments of their day and other edge cases not common today.

Not to mention these people were elite global competitors, so if they felt less sharp at 35, that means they were merely just the top 1% instead of being the top .1%. They still were amazing thinkers and producers after 35.

Just off the top of my head, Stanley Kubrick's career peaked with his decade plus long Lolita, Strangelove, 2001, and Clockwork Orange period in the 1960-70s, which was around his 30-40s. Then nearly 20 years after Lolita, well into his 50's he made The Shining, which is considered an important American film, perhaps not as groundbreaking as the others, but something miles ahead of his younger competitors. So even as these people supposedly age out of their peak years, these super high performers are still amazing. The Oscar winner that year? Kramer vs Kramer, a largely forgotten piece of art and "safe pick" that played to social issues of the time. The best screenplay? Breaking Away, a completely forgotten movie. The Shining is still a beloved classic, cultural icon, horror master-class, an iconic actor's defining role, and a movie studied in film school religiously today and for the foreseeable future.

Then almost a decade later in 1987 at age 59, he directed Full Metal Jacket, a lesser work, but considered one of the best anti-war films, arguably stealing or matching the crown from beloved critic favorites like Apocalypse Now and The Deer Hunter, long after the 60s and 70s fad of anti-war movies faded away and Vietnam a now faded memory and during the right-wing, pro-military, pro-interventionist foreign policy Reagan administration. This was a bold and provocative move you'd associate with a younger director trying to get attention and not a man close to retirement. So even "old" Kubrick was competing on a world class level and doing interesting and challenging things.

A genre horror film from a famous director who hasn't delivered a great film in a decade? An anti-war film in the late 80s on the tail of Top Gun? Both of these genres were fads once and decidedly uncool at the time of their release. This on paper sounds almost foolish, but in practice, an artist of his calibre pulled off something very special in both cases.

For modern people, career peaks are mid-30s. The "wisdom" of two hundred old plus composers and poets is a nice toilet read but isn't scientific at all. Science has its own ideas about aging:

The journals Psychological Science, Science Direct, and Harvard claims various mental peaks come later in life. New vocabulary peaks at 67, learning new information at 50, concentrating at 43, learning new faces 32, etc.

https://nextluxury.com/mens-lifestyle-advice/what-age-do-men...

So yes 35 is not only a good age, its the start of a peak, and a 35 year old modern worker has still another two decades of high performance waiting for them.