IMO he is developing really well. Slowly but steady. He did decent last season as europe debut one, scoring 9 goals for us. The goal vs. Cagliari was his 10th goal for Inter in official matches, and had limited time on the pitch.
In Argentina he is really bossing every game he played. He already has 9 goals for them, in 13 matches. That's impressive if you see the forwards Argentina has.
And he just turned 22. Still very young, far from his peak.
He just needs to keep on working, his father not to talk, and he will become great player, if not even world class.