Extra Inventory Slots On Backpacks Based on Tier

Please add extra inventory slots as a stat to backpacks, giving more slots for higher tiers. The weight capacity is restricting enough as it is, I can't in any way understand why adding another in the form of a 75 slot limit was seen as a good idea. I feel doing this with backpacks is a good compromise if you insist on restricting us further (though I would prefer having our unlimited slots back and just having to deal with weight, personally).