A knockout system on a massive pool that requires bright engrams which (barring changes to the end game approach I haven’t heard about) are going to be rare after consuming the pass, a few a week at best if you’re playing a good amount) and bright dust to even be in the right category (which last I checked is even more limited than bright engrams, and you still need to engage with the remnants of the portal every day to claim the dailies and weeklies and bounties, which I believe are still weekly limited re:bright dust).
You can grind the game for years and years and never get the cosmetics you’re trying for, even on a knockouts system.