I’m just a simple man.
The Cowboys are the richest team in the NFL……but we are cheap
What are we saving this cap space for?
Philosophical change. The Cowboys went out in 2012 and signed one of the most expensive free agent corners on the market, Brandon Carr. While Carr was a better corner than he's given credit for being, the Joneses didn't believe he was worth the contract they gave him. Looking at a few other big contracts they had rewarded that didn't pay dividends as far as winning goes, they changed philosophies. Carr was the tipping point.
What they decided is that the return on investment for entering the NFL free agency feeding frenzy was not worth it. You pay higher prices because everyone is after the best players on the market and you don't always know what you are getting for the cost. They decided it was better to pay players they know fit with the team (i.e. their own) than invest in players they don't know.
They are not cheap. Look at the contracts they gave Elliott (highest for a running back at the time), Lawrence (among the top-paid DEs at that time) and Prescott (one of the top-paid QBs at the time). They just decided it was best to fill gaps in the roster with cheap FAs and then try to upgrade the roster through the draft.
The plan is an overreaction by the Joneses (as always) and is flawed since teams have shown that free agency can be used to help teams reach Super Bowls. What the Joneses' problem was is that they were overpaying for needs in free agency, giving big contracts to maybe the best player at a position of need but not the best available free agents. They needed to be going after difference-makers. Instead, they just gave up on the whole thing and now shop in the discount aisle hoping to find a bargain.