My belief, if you give a coach like Allegri what they want, you win. If you give a coach like Conte what they want, you win. Allegri is not the issue, he is a great coach. HOWEVER, sometimes it comes to a point after some years where fresh ideas are needed. I go back and forth as to whether we are at that stage now I will admit, but Allegri is a great coach regardless.
Definitely were killed by the midfield though, and defense to a lesser extent but even that is affected by the midfield too.