Yes, and that’s also why “career success” here really only means “modern era white collar career success”. In other times and other fields it can look very different.
This definitely is not true, outside of physical domains.
I chose a random domain (philosophers writing their seminal work) and found that most wrote them in their 40s. Kant wrote the critique of pure reason at 57 years old!
This is a pointless discussion though without talking about testosterone and dopamine levels. Doesn't really matter what your IQ is at 60, if your testosterone and dopamine system is that of the average old man you are not going to have the desire to write Leviathan or Critique of Pure Reason.
I chose a random domain (philosophers writing their seminal work) and found that most wrote them in their 40s. Kant wrote the critique of pure reason at 57 years old!