The issue is it turns player wages into a zero sum game. In the NFL, quarterbacks have been taking up a bigger and bigger percentage of the cap, while players in positions that don’t last as long (due to injuries or just aging out) make less as a result. Now, on one hand, it makes sense because QBs have been more impactful to teams over the last 25 years, but at some level, you have to respect players like RBs who take more hits, have shorter careers, and more medical issues after retirement are getting shafted.
What has happened to running backs has to be address in the NFL. It is probably the worst position in football. Your body takes an incredible amount of punishment and you are typically washed up by the end of your rookie contract. Only the truly top running backs manage to get a decent second contract.