There are far too many magic items already. So many that it's impossible to put them in proper context.
As 1varangian said, there are so much items now that it would be almost impossible to find a good place for any of them.
I had a similar thought and one solution I can think of (if Larian wants to keep all those items) are non-specialized traders like Volo. Volo is not technically a trader, because he doesn't have an entry dialogue line to start a trade. But we can do it through the trade icon on the bottom left of the screen, then we can buy a unique ring he has. There are a lot of characters that seem able enough to posses some powerful items. It would make more sense to corpse-loot or bargain for those, than to have them scattered around the map like spilled popcorn.
