2. The Chicago Bears' run defense completely turned it around
This goes back to what Matt Eberflus inherited. When the Chicago Bears fired Matt Nagy, he was just shifting his defense. The Vic Fangio had more of an odd front look, and Chuck Pagano tried to move them to an even look before getting replaced. Sean Desai moved them back to the Fangio ways, but Eberflus was more similar to Pagno in his defensive front. Needless to say, the Bears went three years with the wrong personnel upfront.
They still have work to do to fix the personnel, but the mentality of play is there. They went from, hands down, the worst run defense in the NFL to one of the five best in the NFL. That is a massive turnaround.
Yes, it is not the offensive explosion that fans wanted, but this shows that he can focus on one unit and improve it over the course of a season. Now that the run defense has the players and technique that is required, the focus can go to other places, and we can see growth there.
It is hard to fire a coach when things are not completely falling apart. Going from a miserable defense to a good defense is one season usually does not warrant a firing.