During his time at Juventus, he was still young and not fully developed both physically and mentally, including his finishing skills. Capello taught him many things, helping him grow in every aspect. The Juventus team under Capello was more suited to playing in the league system rather than in Europe—they were hard to beat and tough, but lacked creativity on the European stage.
At Inter, I can confidently say that he was the hero and the key figure in helping Inter win the league. Although Inter was strong at that time, there were even stronger teams like Ferguson's United or Barcelona. Additionally, during his time at Inter, I think he missed many easy tap-in opportunities.
At Barcelona, as we all know, he wanted to be the centerpiece of the attacking unit but couldn’t because Messi was there. He had to adapt to Messi and Pep's plan. He did it, but not well enough, leading to the legendary clash with Pep.
At Milan, he was truly the center of the attack, but his supporting cast wasn’t at a level to compete for the Champions League( at least in the semis anymore). Many players were declining due to age—everyone knows who they are. In the 2010/2011 Serie A season, Ibra played a pivotal role for AC Milan, contributing significantly to their success in clinching the league title.
From 2012 to 2016 at Paris, there were many strong teams like Bayern, Juventus, Barcelona, and Madrid. But he almost did it in 2016; if they hadn’t lost to City, I think he might have achieved it.
Ibra's main drawback is that he needs to be the focal point of the attack to bring out the best in him. He can be marked out of the game by truly great defenders and often fails to perform in crucial matches, especially in the UCL. The media and many others have criticized him for this. Additionally, his finishing in many games often misses easy chances.