Because they sign free agents every year, keep and pay their stars and attract value replacements. They have been to 2 SB in years and won 1.
Its called having a real GM and ownership structure. I know all of this because I can read and see results
They also know how to identify weakness and build a team. Hurts will never be Tom Brady, or even Jordan Love. Ergo, lets get a top flight RB and solid Oline.
Then some teams say "We have the best QB who only chokes in Playoffs, top RB FA too expensive, so we'll get Zeke who is just as good on a bounce back year". LOL