This might have been brought up before since it's kind of obvious. I will nevertheless state my suggestion for you guys.
As of right now the only thing to do with collection points is, well, nothing at all. I am not sure why they went through the trouble of putting it in the game to be honest.
I suggest that they add boons that can be bought for collection points, much like the Sharandar/Dread Ring boons.
This would give players a reason to go back do places where these items drop to get as much points as possible so they can get as many boons as possible. If not boons, then other items could be bought, like Hero's potion or maybe shards or enchantments, whatever!
And after points have been spent, they are no longer viable for spending again. This is why I think boons would make sense. (can't get more than one of each boon so no need for extra points)
Maybe after you complete a collection you unlock a first boon, etc. These does not have to be big boons, depending on how many is put in and how you unlock them I could see useful boons being +100 power.
Now if I see an Orb of the Archmage I just cringe and sell it for 1.6 gold. I thought of this item because I have gotten two of them as drops from Valindra (10500 gs dungeon drops only t1 gear or BoP for set classes, lol)
I could use it to sell it on AH since prices for ALL ITEMS would go up if every item had its use for someone!
Same idea can be used for artifact/companion points. This would make people BUY MORE stuff, and PLAY MORE!
As of right now you have tons and tons of content that most players only see maybe two times since after leveling you don't go back. I have so many ideas that could be used quite easily with content already in the game. Ideas that would make people play more and spend more. Most of these are obvious, yet nothing is happening.