Nope in the 90s you heard that a players prime was in 26, 27. But today we are seeing more rapid declines imo.
Delayed reward cycle, especially back when media was slower (no internet). Applies to media/fan attention as well as coaches/GMs. Player is an up and comer, player peaks at 23-24, but it takes a couple more years of people heaping praise on them before they attain the status of older stars who came before them, player is now 26-27 but their reputation is just peaking, player turns 30 and is only just starting to be considered a long time star, they ride that well into their 30s.
Basically, the perception of players is delayed, but not as much now as it used to be because people are more up to date because of the internet, and also because the salary cap means older players who have huge contracts are less appealing.
Still happens to an extent, people don't want to recognize players for how good they are until they've gone out and "proven" it. But if you wait until after a player has a career year before recognizing how good then by definition you are not appreciating them fully during their peak.