The Broncos are only better based on a trade for an elite quarterback, but considering they beat us without one last year with a bunch of their top guys out, it's not a stretch.
They have an elite defense with elite players.
The Colts, Titans, Browns are all playoff teams, we were not a playoff team. We beat one winning team last year. You are making very optimistic projections about improvement based on guys just getting better and some roster additions which were frankly trumped by what other teams did.
And I don't know how good you thought our defense was last year, but it wasn't nearly as good as you think. We were 20th in total defense, 23 in total pass defense, 16th in total run defense, 10th in sacks, 1st in turnovers, which is not stable and will regress bigly based on past leaders in that stat.
We were 6th in scoring defense, impressive, then you consider we played the 32d offense twice, 29th with a backup, 28th twice, 27th, 23d, the 15th with a backup. Pump the brakes a bit