I have to admit that I have not seen enough of him to properly judge him, so it could well be true that he is a lost cause and will never be a valuable Player.
The Point i am trying to make though is that we should be looking more at Players who have something "Special" with them even though they lack in other Areas, because those are the Players that will eventually become world class. A Player like Gomes will never become world class evn though he is decent in most Areas, because he does not have anything Special about him. He wont magically become a great dribbler over night, Whereas a Player like adama, who already has incredible Dribbling and physical ability, could become a great Player if he improves his weaknesses.
Gomes is average in all areas and thus he can't turn into a world class player.
But that example doesn't turn likes of Adama into a world class players either.
Adama is, on the other hand, special in dribbling, but is extremely flawed in IQ, so at the end of the day, he will be a way weaker player than Andre Gomes who is average in everything.
When you are average in everything, you can at least turn into a useful 1st division level of a footballer.
Adama and other players with horrible flaws (Halilovic) will struggle to turn into even a 1st division players.
So:
1. if you are average in all areas=you won't turn into a Barca level of a player
2. if you are a world class in some areas and horrible in others=you won't turn into a Barca level of a player
To turn into a Barca's level, you need to either:
1. be world class in everything (almost impossible)
2. or be a world class in some areas and at least average/playable in other areas
So, regarding your post, neither Gomes or Adama are good examples.
None of them will turn into anything special.
And yet, Gomes will end as a more useful player since he is an allrounder.
In the future, when you'll watch at young gems, whenever they have a huge flaw, more or less they are dead for turning into a world class players.
Some examples of flaws which you can't fix are: injury proneness, extremely weak physique (like very slow player, extremely short player, or too weak physically like Denis, extremely poor stamina like Bernardo Silva etc), extremely low IQ (Adama, Halilovic), extremely bad professionalism and bad temper (Halilovic, Quaresma), extremely scared player (Samper), horrible understanding of tactics etc.
So, even if a player can dribble past 100 players, it won't help if he has extremely low IQ or bad understanding of tactics.
Also, if he has the best passing and the best vision in the world, it won't help if he is extremely weak physically, slow as a turtle etc (Seri).
Again, a player in 2018' shouldn't have a huge flaw anymore.
The bar has been raised very high lately and if you are not good in all areas, you won't make it in a professional football.
15-20 years ago, it was possible to have good CAMs with a poor workrate, with slow pace or with a weak physique.
Today, you can't survive with that anymore on the highest level.
15-20 years ago, you could have survived with CDMs with good tackling and horrible passes. Their only duty was to defend.
You can't play a player like Mascherano as a Cdm anymore in 2018. The bar has been raised higher and all midfielders need to defend, pass, create, run, work, score etc.
So, Adama could have been a good player in 1987 and 1997 when one dimensional players (who were extremely good in something) could have played at the highest level.
Today, he will struggle to turn into a starter even in an English 2nd tier division.