This is just my point of view on how vendors (specifically Crucible, Vangaurd and Drifter) should be more important. For Gear, make the vendors sell all weapons and armor with rotating perks at reset. And if we rank up make it where it was like Destiny 1 where you could choose between a weapon or armor package. Another thing that could work out well is bring more bounties like Nightahade but with armor as well.
How about refreshing the loot pool for the vendors and world drops? Most of us are tired of the same old drops and rewards since day one. The limited random perks helped for a while, but even that has gotten stale. Most of the vendor rewards and world drops have become the equivalent of an Edge Transit by now. * Choosing between weapons and armor was a great addition in D1 and would be most welcomed in D2.