With Kanai’s cube recipe to convert materials from one type to another that basically makes all crafting materials equal. So for crafting purposes rare items are pure garbage for getting materials and white items are the best for getting materials.
For every yellow you get 1 crafting material for every white you get 2-8 or something to that effect and blues something in between.
So my issue is yellow items in end game are pure garbage to collect materials since it is only one per item. Which seems really silly considering they are supposed to be the superior item.
So my suggestion is to make it when you salvage an item you get the items base salvage plus salvage for other materials that are below it’s quality. For example I salvage a white item and it gives me white item parts. If I salvage a yellow item I will get the one yellow material plus some blue material plus some white material. If I salvage a legendary I will get the legendary material plus yellow plus blue plus white.
Otherwise in terms of crafting white items are the superior choice and that seems really silly to me.