Hate to use this as an excuse, but health (in particular) at CB, OT, OLB hurt this team in 2016 & 2017 (QB not withstanding).
Sure they overcame injuries in 2010, but (IMO) they got freaking lucky that year. They were healthy (and a juggernaut) in 2011 while being relatively healthy. Unfortunately they may have peaked too early that season.
Better team health will go a long way to getting back to the playoffs. Rolling the dice in FA and the draft might help, but so does staying healthy.