The problem with Pogba is that he has failed to develop vital parts of his game because of his immense physical talent. He's never had to learn how to resist a press by quick decisions and passes because even if a player could press him, he would just shield them from the ball and shrug them off. But teams have learned this and actively hunt him inside our own half when pressing us because he will try his shielding technique on one while the other player nicks the ball off of him. Essentially, Pogba is a giant Ozil with better goalscoring prowess at this point. Meaning he's a player that will float around while playing passes that only a select few in football can, and will have moments of genius combined with large portions of the game passing him by. Both players are fantastic footballers but both struggle to fit into a side in the modern game because every top team has turned into a high pressing manic style of defending to win the ball high up the pitch and create easy attacking opportunities. Neither of these players are any good at pressing or defensive work, so they can't contribute to their own teams pressing which causes a disjointed effort and results in teams bypassing them too easily.
Pogba being put into a slower game 20 years ago would have been lauded as a Ballon D'or candidate, but the tempo of the game now requires more energy, decisiveness, and cohesiveness as a unit for a team to have success at the top level, which is why a team like Liverpool has workhorses that run themselves into the ground as a unit. They don't need any genius passers of the ball (although TAA is one with crosses) because a large portion of their goals come from winning the ball back and immediately being in 3v3 situations and isolating their forwards onto defenders in positive situations, so build-up play isn't as vital. It's also why they can look toothless in games where a team is content to defend and just hoof the ball up to attackers against them, as they then have to rely on numerous crosses from their fullbacks or a bit of individual magic from the forwards. It still works most of the time, but it's the only flaw in Klopp's system.