Amir is no longer going to reach the level of Wasim, that much was clear ever since he was banned for five years. That time away from the game arrested (no pun intended) his development and also robbed him of a bunch of wickets.
He will however, still become a great bowler in his own right with an average in the 24-27 range in both formats, 300+ wickets in each and plenty of match-winning performances, InshAllah.
Since he's no Wasim, it's understandable that he's been struggling in the UAE and Sri Lanka. He hasn't developed reverse-swing yet and lacks the explosive pace of Waqar or Akhtar.
With time, however, he should be more successful in Asia as well.