The reason why we needed to change how extractions worked is because it was becoming clear that players were increasingly seeing "vanilla" enhancive items as mere delivery vehicles for orbs rather than being actual items in their own right. Things like worn location, crumbly status, maximum charges, alternative item functions, weight, and so on are all properties of items that we try to vary to create items that provide interesting choices and character building "puzzles" and options. The ability to relatively trivially negate all those other properties to extract one property at its full value was a serious design flaw in fusion that needed to be fixed.
Duskruin put a lot of enhancive items out (and so does the treasure system), but the reason they can do so is because you often need to stretch a bit (or a lot) to actually use the items in their intended form. That is an intended part of the entire inventory system. If, instead, all those items' enhancive propertiers are just harvest-able to place in a single optimized item, then that is quite a big unintended bypass of most of the inventory system. Fusion extactions, as previously handled, were not sustainable going foward, unfortunately.