Inventory clean up

There are too many items stored in my inventory that I either: have too many of in place already, do not need/want anymore, no longer have a use/place for, or have accumulated unintentionally over time. Why can I still not sell/recycle/discard these items? A landfill update, or a waste ground that expands when discarded items are added would be a welcomed solution, or just the ability to sell unwanted items (multiple items at once) would be nice!