People keep going on about talent and lack of application.
For me, I don't think that is quite true. I think the issue people have had assessing Pogba is what they define as talent. Talent for me isn't just ability on the ball, but it's also intelligence, movement, work rate, stamina and decision making. Pogba didn't have those things. He was a physically strong player who had a great long pass, good shooting ability and could dribble when space was provided. For a greater comparison, in England, what made Gerrard, Lampard so special? Players with similar attacking technical abilities.
These players were quick decision makers. They had great anticipation and intensity, which meant they could usually win the midfield battles or adapt appropriately. They had great stamina and work rate, which meant that they were consistently active. When you then add their attacking technical skills, then you got truly world class players. In the Premier League, you need those physical and mental factors to perform well. Pogba didn't have the speed of thought or movement to be nearly as effective as we all hoped he would be. He also didn't have the awareness or patience of Yaya Toure to play according to his strengths.