There have been some past seasons with great armor sets and unlocks that are unavailable now. I would love it if Destiny 2 had a similar system as Halo Infinite where you can switch to older season passes and grind to unlock cosmetics from the past. I would gladly spend my wallet on past seasonal armor such as the Season of the Seraph or Season of Dawn.
I believe it would also increase the longevity of the game by allowing players to grind out previous season passes. That's all I have to say.