Nope. He began slowing down in his development even at Arsenal (personally I felt that the move to the number 10 was a bad choice for his development and it was more about Wenger trying to cover glaring holes in his team) and the move to Barca didn't work at all. He has performed quite decently there – I actually liked their partnership with Messi where Cesc played as a false 9/10, but it certainly didn't make the best use of his best qualities. At Chelsea he has performed very well as a deep-lying playmaker and almost broke an assist record, but he was hardly one of the best players in the league, let alone in the world at that point – and that was his potential.
He should've been what De Bruyne is now or Pirlo was earlier. His passing from deeper positions was out of his world, his shooting was great, and overall he was a very complete midfielder. Weirdly enough, a transfer to Real Madrid probably would've worked out better for him. He had a great career, but he could've achieved all-time greatness, he had all the tools to do so.