As Arsene Wenger always say: quick players age better if it isn't for injuries.
Losing a step means they are still quick, losing 2 means they are now average speed. Slow player lise a step and now they are easy to contain.
Both Messi and CR7 were super athletic, in different ways, and it helped them to have longer career. A player like Busquets or even Xavi were done and dusted by 32.
I also tend to agree that promoting players early is bad for their careers, the athletic had a nice piece about it, designed for Barca specifically btw with the likes of Gavi, Fati etc discussed. The main conclusion I get from it was that, at the end those players are rarity to ever have a conclusive evidence about it, so it is always up for opinion, but signs of players suffering from being used too much too early is there.
But then again, you can always point out to something to each case and say it wasn't being too early.
Hopefully, Lamine will be an exception, and the club can take care of him.