For me Ozil represents the best and worst of the 2nd half of AW's tenure post Fabregas.
Not just as a player but also in terms of policy/priorities/philosophy, squad building & balance, managerial style (putting players ahead of the team or club, which is why they love him).
An artiste not an artisan, indulged, frustrating, brilliant, but not a legend other than in terms of what could have been had AW pushed the boat any built a team around him fit for purpose. Even without that IMO Ozil could have been as good/instrumental as DB10, but his attitude prevented him from doing so.
IMO his issues were not the new club deal but the fall out following the WC. I'd not be surprised if he felt every bit as abandoned/isolated by the club as AW re his departure, and more so following AW's departure and his changed status with the club. The worst decisions over the past 3 seasons by club and player resulted in retaining the status quo which was never going to improve or change post AW's departure.