Many factors to be honest.
Usually kids around 13-18 can grind way more, plays braindead playstyle (pure aim) when a mature or older player is more "brain" than aim itself
I think the more knowledge you have in a game, especially in FPS, makes you to play way more safer than when you're younger since you take more risks and people cannot read your game properly at all.
It happened in CS, most CS teams who win always had 1-2 young players to do this part of job while older players played more supportive.
A good team need balance these characteristics very well, If I'm correctly, some teams in Valorant prefer to let their duelists to play more "free" to abuse these things plus duelist has escape abilities, so you let your duelist only to focus in killing by his pace while other members, especially with more knowledge try to help him.
It think it's also something natural for some people to play like that, but as soon you have more and more knowledge in a game you'll stop taking too many risks.
It's complicated because there's no escaping it, as time goes by a player will acquire more and more experience and this will affect their way of playing, so he will play safer naturally.
I think younger players are more creative, while older players tend to be more logical overall, it is not only AIM difference at all.
When you're young, the best thing you have is the adrenaline of winning a clutch by making insane plays, there's no better feeling.
But when you're old, the best thing you'll ever feel is actually WINNING itself, and not just clutching at all.
Pretty sure most of players around 20-23 start feeling way more less "adrenaline" during clutch situations than they were teenagers.