This was definitely a thing just back in the 2000s. You had guys like melo, tmac, Paul pierce, wade, Dwight ect all decline in this age range or way before. People always mentioned lebron still being so good when he was 33. At first that seemed like an anomaly. Now, you have guys like curry, kd, kawhi, dame, lebron still(lol) jimmy butler, all still being in their prime at 33+. Is it an advancement in technology and medicine? Something else?
Interesting you should ask that when people are moaning and bitching about players resting games now. It’s almost like the teams know what they are doing and they are prolonging player’s careers.
On top of all kinds of other stuff with sport science, training, nutrition, etc…