TBH with him.. Ogbonna is not that bad technically speaking and defends well in the air...also he is atghletic..........but he has 3 very bad habits:
1-Tends to lose awareness of his surroundings
2-Is not clutch with the ball at his feet.
3-After he loses a ball, theres no urge in fixing his mistake.
And for a defender...this 3 things can potentially end in a goal aaginst.