I favor a return to 1e-style treasure types based on the type and number of monsters rather than on encounter difficulty per se.
I think of it like this: I'm generating treasure / equipment for for a group. It's a goblin tribe. They currently lair in a forest, so I check to see how they get their equipment. 2 ways, they scavenge (raid) and craft their own. On the very large scale, this region's goblin culture is pretty savvy with woodworking, so they build their own spears, wooden shields, huts, grass armor, and a lot of NPC class stuff that would take time to really list out.
How much do they have? That's a measure of how many there are, how much material they have on hand, how long they've been able to work without interruption (lair invasion), and so on. This is all Economy game stuff.
Other stuff comes from raiding parties. Who's nearby that they steal from? What other creatures territories overlap with their own? Are there the remnants of any past civilizations goods to be found?
The cool thing is, there can be treasure monsters have crafted themselves, stuff they just rooted around and found and are now using it to the degree to which they understand it, and treasure there could be treasure simply sitting there completely unrecognized.
Not everyone can see magical auras, so sometimes one of those swords in the rack really is "magicked", if old and beat up. Other times it's that stone pillar with weird pictures that actually mean something once you understand the context (like the goblin forest is built upon the remnants of a volcano and the pillar's builders mark this spot the edge of where a cursed city fell into an abyss below when the earth began to shoot fire and rock).
The thing is, for me, Treasure Types just didn't work or make much sense. Yeah, individual treasure was nice, but I could never make heads or tales of the rationales for the rest.