I don't want to say things like that because there are a lot of horror stories in football. Players that would've been a lot better if they only got the proper chance and were put in the league and team where they can play to their full potential.
Inter gave Icardi and Martinez a proper chance, but on the other hand we also don't trust our youngsters all that much and we also didn't really believe in Coutinho. Ofc it's hard to say which players would pan out, coaches try summer camps to see if there are any gems in the club, but even that doesn't really show everything the coach and staff wants to know.
There are so many footballers that actually can ball. They just need to get into the right club at the right time. Which is kinda why you can still see some "bad" players playing better in a different club or "good" players being shit somewhere else.
TL;DR Schick is a good football player, I could see him being a beast in current Inter team.