NFL owners will always win just because of the nature of the sport.
You have a relative handful of brehs making beaucoup dollars...which allows them the opportunity to think about the future and long-term interests of the game.
Then, you have a much larger contingent of brehs that are one missed tackle, tweaked hammy or slick remark away from either getting cut or sent to the practice squad. Those guys will sign off on whatever as long as you throw them a couple of bones.
So....NFL owners know the players have an 80/20 or 90/10 situation where the bulk of dudes are just trying to maximize their $$$ for 3 to 5 years before washing out. The guys good enough to get second contracts and actually make millions (think Dalton Schultz-level and up) have the perspective of a 30,000 ft view and know that a short-term compromise with perks always comes at the cost of long-term goals. But the guys making comfortable legit money that can stay in the league 8-10 years or more....are a (relatively) small percentage.
NFL leadership appeals to the 80% because they can't afford work stoppages. You'd need a generation of fringe NFL players born in the late 90s and early 00s (the young guys out there right now) to sacrifice their careers for the future generations. The Lamar Jackson's and CeeDee Lamb's of the world are not a big enough percentage of the NFL to influence negotiations. It's asking a lot of the bottom 80% of yung bois to sacrifice their whole careers for benefits they themselves won't enjoy.
NFL owners understand human nature and use it to their advantage. If you ever DID get a generation willing to make that kind of sacrifice, the NFLPA would gain a massive advantage....but it's unclear they'd know how to use it anyway based on what we've seen from them.