I am such a pack rat, both in real life and in games... And sadly yes, WoW simply doesn't have enough storage space available. Getting tokens, pets and mounts out of the bank/backpack space is a huge boon, but most of my characters by the time they hit 70 are working on 2-3 sets of armor at least. Plus all the items that can't be replaced easily or at all like past rewards. I may never use Benediction again, but I'll never get rid of it.

Then there's crafting materials and consumables. Some characters stockpile things for other characters that are levelling, others stockpile materials or consumables so I never have to worry about running out when I need something. Even going though my bags to aggressively prune out unneeded things and send stuff to bank alts, my main characters are always fighting the battle of the backpack bulge.