95% of young players don't make it through big clubs to the first team, on average. We are clearly trying to copy the 'Barca/Bayern model' with our own young players, and we do have some very interesting ones, just not in our first team squad.
Only super talents like Pogba break right through into teams, and even then it doesn't happen right away. Look at him with United. Depends on the coach, tactics used, and whether the team can afford to allow them time to integrate.