Panthers went to the playoffs four times between 2013-2017 and The lost once in the wildcard round, twice in divisional rounds, and once in the SB (after being up with a big lead).
Kansas City went to the playoffs four times in the last five years as well. They lost two divisional games and two wild card games (only winning once in those seasons).
Colts went to the playoffs five times between 2009 and 2014. They lost a SB, two wildcard games, a divisional game, and a conference championship.
Falcons went to the playoffs six times in the last ten years. They lost two wildcard games, two divisional games, a championship game, and a SB.
Steelers went to the playoffs four times in the last six years and six times in the last eight years. They lost in the SB once, the two wildcard games, and two divisional games.
Sounds to me as though they are far from a failure. Calling this team a failure in any stretch of the imagination is a joke. Yes, I get the stupid all-or-nothing black-and-white you fail if you don't win the SB. However, the reality of the situation is that only 14 teams have won the SB since 1975. Think about that for a second. in the last 43 years, not even half the teams have won a SB. Moreover, only nine teams have won a SB since 2004. And, the Steelers are in first place in the first list and tied for second in the second list. Failure? Not even close. "Most successful team to fail to make a SB since 2011?" Sure. Failure? What a joke.