This is a good thing.
While you do have some teams with prolonged droughts in the NFL it always seems like every team is poised to be a contender within a year or two. Don't get that sense in the NBA, MLB, or NHL. While I was certainly happy with NEP prolonged success for twenty years the NFL is designed to prevent that. Parity is good for the league.
Yeah, plus you can still have your perennial contenders like the Chiefs and Bills if they are smart enough and have the right QB. In the NBA, the star players only want to play on Superteams and it kinda screwed up the league. Not impossible to come back from last place, but if you can't reload in free agency, you're kinda stuck with tanking for a few years.
Players take so long to develop in MLB that you won't know if your draft pick flamed out until it's been 6 years already. The top free agents are usually on the wrong side of 30 too, so you always overpay in terms of money and years.
NFL is the best for parity by far.