The Eagles are only an extreme example bc Howie has obliterated a cap loophole that he's more than willing to mortgage the future for current success, knowing he either won't be here when it implodes or will have to reset it anyone and take the hit during a short rebuild. He's willing to do something in the short-term that other GMs are not....2x the void money of the next team (SF) and 5.5x that of Miami.....and since he drafted so incredibly well, he has the perfect window to do so before it becomes unmanageable.You can remove the sleight of hand from contracts, but it doesn’t change the main issue the NFL has.
Player salaries have risen just as fast, or faster, than the salary cap. The amount of money these players get makes it close to impossible to build a competitive team and stay cap compliant. Obviously the Eagles are an extreme example but basically every team with a QB off their rookie contract has to do it to compete.
I agree that players will push hard for these contracts in the next CBA, but it will only make it more difficult for teams to compete. Some players make over $2M a game; a short term IR stint is millions of lost dollars. It’s not like Baseball where there are 162 games and the highest paid player makes ~$400K a game.
If the cap didn't have those loopholes, the Eagles would not be having this success because to your point, current salaries, especially for certain positions, would make it impossible to build a team of that nature. Some of their better players would have moved on to other teams for money.