Yeah I definitely do not need 5 different Headhunter cards. But many of the Div cards are designed by supporters who paid a lot of money for it so its going to feel bad if they remove it. I don't even know how you fix this personally.
Stuff I would have it so that it never drops:
*Flasks. After a certain point, all the white flasks should be able to be purchasable from vendors (like the Stibnite/Jade flasks). There is 0 reason for these to be dropping in maps. They can slightly increase rate of Glassblower drops to compensate for those people who like to pick up 20% quality flasks for a Glassblower.
*Dramatically lower the type of weapons and armors there are. It's tougher for armor because you need one for each type of stat (armor/evasion/ES then hybrids so 6 T1 basedsfor each slot and then the Atlas bases). I definitely don't need there to be like 4 different types of Rapiers/Foils though. I honestly think that basic white and magic items shouldn't be dropping in the game, if you want specific white bases you should be able to just buy them from vendors for cheap (like a Transmute). The Atlas/desirable bases should be drop only of course. Would also cut back on people putting white items on their loot filters that they need for Chancing or other use. Of course vendors would need to upgrade with Atlas or character progression so that they start selling high item level whites and those should be a bit more expensive.
*Remove all the currency shards (except the top tier ones like Exalted and Mirror shards). I definitely do not need there to be a Transmute shard dropping out in the wild. Hell I don't even need there to be a Chaos shard dropping in the wild. Selling items shouldn't give you shards either. 1 unique = 1 Alch, 1 rare unid item = 1 transmute, 1 rare id item with no special stats = 1 alteration, 1 rare id item with a special stat = 1 alteration 1 alch or 2 alterations. I also think Blacksmiths and Armorsmiths have no real place in the game as drops... just have a vendor quality up an item for you for like an Alteration or something. Hell I would say the same for Glassblowers... qualitying up basic items offers 0 depth to the game. Quality for gems should stay because its quite important for specific gems and Gemcutters are actually valuable drops that you can sell for more than a chaos.
*They have to do something about the Splinters because it's really damn annoying. I know why they do it... it's a far preferable system to the Beast boss system where you can go an entire league without seeing a Beast boss because its RNG gated versus gathering splinters slowly but surely (less RNG dependent, more grind dependent). I would much rather Breachstones be like 20 splinters to build up to but each splinter drops less frequently. Would actually add value to these drops. And for the LOVE of god, have them drop at the end of the encounter as a single stack like Simulacrum. Same for Perandus coins but that whole Perandus system needs a rework anyway.
*Stuff that is stackable in premium stash tabs should be stackable in regular inventory too. I see no reason why Atziri fragments are stackable in premium fragment tabs but not in regular inventory. This applies to other items in the game as well.
*Picking a currency item of the same type should auto pick up the same currency item in a large radius. So if you drop a bunch of Chaos in a vicinity, then picking one auto picks all the others. Games already do this. And please increase loot pick up radius.
*A lot of the Essences tiers can be cut down. The same applies for other similar things.
*Remove Incubators from the game. Instead of dropping Incubators... why not just have that specific item drop instead? A completely wasted system IMO.
*Oils and Catalysts shouldn't be droppable anymore. Just like with other quality items, you can have Tane upgrade items when you talk to him for a price. Same for Oils and Cassia, you can just have the annoints that you want from a drop down menu (or open up the passive tree to pick a notable) and then you pay for the cost. Such an elegant and easy system, GGG doesn't have to make slot for these items anymore either!
*Veil system needs an entire rework. You should unlock crafts from simple encounters with the Syndicate. Fight Elreon lvl3 as a leader of a safehouse, unlock all of his special jewelry recipes. Beat a certain safehouse, get a bunch of recipes unlocked. No more veil items being dropped because they are pretty much always worthless and take up inventory slot. Aisling can still drop double unveil mods that you can unveil and unveiling them instantly unlocks the 3 given options (so a single rare item can unlock 6 recipes straight up).
*Remove Talisman drops completely. Keep the Jorgin crafting bench and allow us to Annoint vaaled items.
*Probably redo/remove the Vial system for Incursion items. Just have the actual item drop instead at the end and the Altar also spawn in the room after beating the boss. Good thing is that you don't really get that many Vials to begin with but it's just another thing that doesn't need to be in the game.
*I don't have a good enough idea on how to cut down on the Divination cards but a lot of the low tier/useless ones should be removed for sure.
And as stated before, bulk/currency items should be sold through an automated system but not for uniques/rares other valuable items that have variants (a Chaos orb is a Chaos orb no matter who has it but a jewel can have different rolls).