There are literally thousands of players who are 21. The problem is he has shown no aptitude at all to somehow magically develop his positioning and awareness to a high standard which you somehow believe based purely off the fact he is 21.
When the whole hope is for him to develop skill sets which he has shown to be very weak at then chances are he just isn't any good.
I don't understand your logic. Since there are thousands of players at similar age it will make it impossible for him to develop specific attributes ? There's no "magic" in developing positioning and awareness when we're talking about a 21 years old midfielder. He's still young and plenty of time for him to improve and develop.
If we want youngsters to break from the academy we need patience on them.