The problem is virtually nothing was his fault.
His job was to produce offense and tilt the ice, and he did that. Well. Without nearly the help that the current Oilers team has. This group is a lot more than just the old Oilers with Adam Larsson and without Taylor Hall.
If you put Adam Larsson on any Oilers team prior to Connor McDavid and took Hall off, they're worse. Certain members of this board are ridiculously single-minded and seem to have no problem conflating the success of a team with the addition or subtraction of a single player.
The Oilers were at the bottom of the league every year Hall was on the team outside of the lockout shortened season in which they were spiraling towards the basement. Not blaming Hall for that although he should own some of the blame as one of the team leaders all those years but I have a hard time believing that the Oilers would have been even worse with Larsson and no Hall.
Hell, they were at the bottom of the league even with McDavid and Talbot playing lights out, not to mention Hall as well.
My point is that having a solid defense is paramount in this league. Larsson changes the entire complexion of the defense. It allows Klefbom more freedom to activate offensively and it knocks down Sekera and Benning into roles that are more suited for their abilities. If Larsson had been around prior to McDavid coming here, players like Petry would have been much better because he would have been playing in the Sekera role as a support D and not as a #1, same goes for Schultz who would have been properly sheltered. One dimensional wingers, even if that dimension is high end like driving offense in Hall's case, are limited in how much they can impact overall team success.
There are many factors that have driven Oiler success this season like more balanced forward group, healthy Klefbom, more defensive depth, internal growth and 2nd season under a competent coaching system but Larsson is right up there at the top. If you swap out Larsson for Hall, this is a worse team and possibly significantly so. You'd probably have to take Lucic out too because I firmly believe that the Hall trade facilitated him signing here.