2) Competent coaching
The Broncos, for the first time since Gary Kubiak, have competent coaching across all of the phases of the game. The Broncos did not need their fans to count down the play clock for the head coach, did not need to hire a time management coach, and had all three of the main coaches, head coach and coordinators, last through the entire season.
The Broncos defense under Vance Joseph started historically bad but turned around their play in a way that put the Broncos back into the playoff conversation. The defense under Joseph and his assistants, including Christian Parker, held Patrick Mahomes and Josh Allen to respectable passing numbers and created turnovers in massive numbers against those two, and others such as the multiple quarterbacks they faced against Cleveland, and Minnesota's Josh Dobbs.
The Broncos finally have competence across the board on their coaching staff, and it gives much reason to hope for the future.