How is it that we stay in salary cap purgatory for YEARS and still can't be competitive?

You think that we'd eventually shed some of the cap problems and start rebuilding this roster. We're nowhere close to being a Super Bowl contender. We can't even make the playoffs. Yet, we consistently have the oldest and most expensive roster. I get doing that in the last years of the Brees era. It makes no sense 4 years later.