The "good old days" where you can annually stash 40-something players on your reserve list (thereby completely restricting any halfway decent player from ever achieving free agency) simply could not function in today's sports and economic climate. Furthermore, the vast majority of fans do not pine for a return to those days.
I am not going to debate the semantics of the word "parity" but the current system has the goal of giving every team an equal platform to start from. In other words, you can't radically out-earn and outspend other teams like in baseball. If you win, it is because you outsmarted everyone, not because you outspent them. Now, obviously, luck plays a big factor with regards to injuries and the fact that so many games can come down to a single play or a single call. The system also gives bad teams a benefit in getting the earlier selections in the subsequent draft.
And it's true; the difference from top to bottom today is less than it used to be. A team can radically change their fortunes with a simple thing like a key addition, a QB that dramatically improves, a new coaching staff, etc. The system has been in place for roughly 20 years so I am not quite sure we can call it "new." As such, the NFL has achieved unprecedented growth and prosperity during that time.
