This is a ridiculous leap of logic.
His [young] age doesn't dictate a points-growth like that just because he's averaging 21 ppg. He's averaging that amount of points because he's free to put up shots on high volume on a bad team - it's why his efficiency is in the dirt and opposition teams don't treat them with any respect. Tyreke Evans averaged 20 points at the same age and look where he is now. You can't just extrapolate stats like that all because you like a player.
Regardless of all that, the amount of points he's averaging and will average in the future is inconsequential. It's how impactful and efficient he is. That's why it doesn't make any cotdamn sense for y'all to be acting like he's broken some threshold where he's become whatever you think he is.
This is predictable from you though.
You really only care about how aesthetically-pleasing a player's game is, it's why every player you stan fits this mold (Penny, Steph, Kyrie, LaMelo, Kobe, Cam Reddish, Sharife Cooper, Jordan Clarkson etc). The same reason you try to downplay the likes of Cade and Bron. Which is your prerogative, but it doesn't really mean much in the grand scheme of things. You gas players because of how good they look, and not how good they actually are.