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?
LeBron and Butler actually have a lot in common, although LeBron is obviously better. But both of them play a very physical game that doesn’t depend on pure athleticism.
The difference is that LeBron is a tank who seemingly never got injured in his prime, whereas Butler rarely plays a full season and just needs to focus on being healthy in the playoffs. Even in the playoffs, though, Butler has a harder time sustaining that physical style of play.
Look at last season, where Butler was clearly hobbled in the Finals. Look at game five of the 2020 Finals, where Butler matched LeBron and came out the victor — but had nothing left in game six.