I play on the same server as you. I don't feel the amount of gold dropping from individual adds has dropped, but the frequency of enemies corpses containing anything lootable has been lower for a good few months now which will affect the overall amount of gold collected.

From what I've read, there is a general cooldown on loot in the game, by which I mean that if you've been doing a lot of looting within a certain period of time, the amount of loot that drops will dramatically decrease or even stop completely for a while. This can be particularly noticeable in public dungeons, but isn't limited to public dungeons by any means. I think it's just that public dungeons are often great farming and looting locations in general, due to being much larger than most delves, having multiple bosses, and often having a large number of lootable containers. Certain types of delves can also be good for looting, such as Dwarven delves that have a large number of urns.

Anyway, I've often noticed that I can go into a delve, public dungeon, or group dungeon and get a huge amount of loot from containers, mobs, and bosses, but then I can go into another one-- or keep running the circuit in the same delve or public dungeon-- and after a while it will seem like none of the mobs are dropping anything anymore, or nearly all of the containers in the next delve will be empty, etc.

A few months ago this came up in zone chat, because someone asked whether a particular ancestral tomb in Vvardenfell had been nerfed, as it used to be a great place to farm loot from all of the urns insude, but they had just gone there and all of the urns seemed to be empty. I decided to go check it out, and was finding a lot of loot (gold, lockpicks, and things like recipes or blueprints) in the urns, so I mentioned in zone chat that I was finding a lot if loot in the urns, and suggested that if they'd been doing a lot of looting somewhere else before going into the ancestral tomb then that might be why they were suddenly getting no loot, due to the apparent cooldown period on looting.