There are so many items in this game with the sole purpose of cluttering up inventory after you finish upgrading everything.

Base Game
Supplies, Leather, Iron Ore, Ingots
Why those weren't sellable since launch is beyond me.

River Raids
Foreign Supplies
Just give Vagn a proper shop or let us sell the leftovers.

• IDEA: Vagn should have a permanent shop to let you exchange foreign supplies for silver, titanium, iron, leather, perhaps a weekly Opal deal (20 Opal for 500-600 foreign supplies). Maybe even a bigger selection of runes. This would give more incentive and replayability on those River Raids.

Fabric
The new River Raid maps added more fabric for no reason (quiver/rations fully upgraded and no altars left).

Wrath of the Druids
Trade post supplies
Why those weren't sellable since the DLC released (Farmable on Royal Demands prevents player being unable to upgrade trade posts).
Luxuries, Delicacies, Texts, Clothing
At least those are sellable which makes them better than anything else on this list. I just wish you could just straight up sell those at any quantity to Azar instead of the needlessly slow way we have right now.

• IDEA: Let us collect and sell those from the Irish Outpost building on Ravensthorpe, it is a useless building and would be a lot more practical than loading Ireland just to collect and sell those, specially on the previous generation consoles considering the atrocious loading times on this game.

Siege of Paris
Raw Materials
For some reason, monasteries in Francia added more of those. Can't be used for anything

In my opinion, silver is an important end-game resource since it can be exchanged for titanium (the true bottleneck resource when upgrading all the gear) and the expensive Scrolls of Knowledge.

Regarding the new River Raid maps, having more leather and iron ore than I could ever need, there is no reason for raiding in Ireland and Francia anymore since those maps barely yield any silver to loot when compared to the raids in England. They serve a purpose for completing the quests/getting the new gear pieces, but there is no reward on them to incentivize replayability which is the whole point of river raids in the first place, to be a gameplay loop for the end-game. It is ironic that farms in England have more riches than developed villages/monastery/estate in Francia (supposed to be a land of riches and abundance).

The rivers in Ireland and Francia should have a lot more silver and sellable junk to loot, but that might be too much for Ubisoft to consider. Enabling the player to sell at least the leather and iron ore from the chests adds a little reward to incentivize replayability on the new maps.

I completely agree....

there are a number of objects (almost ghost) whose existence is named, but in fact they exist only in the form of an "icon" in the inventory:
feathers, balls, broken armor or broken bows ...
but also many objects of secondary missions, such as rings or medallions .. ??

why?