I don't know why he left, there were stories about him and Poch not having the best relationship. Since him and Walker we've had Aurier and Doherty who are both worse players than those 2.Agree. Had a poor final season but still a technically proficient footballer. He offers something different from Aurier - they both have weaknesses but I don't think we've improved on him. Perhaps he needed (or wanted) a change.
It's no wonder our team has got worse, we've just failed to replace adequately too many of the players we relied on between 2016-2018 when we were actually quite good.