It's almost assuredly too late for this to happen in DOS 2, but not in a DOS 3 or other future Larian game with crafting.
Each town should have one vendor who sells about 30 completely random crafting ingredients, and nothing else. Unlike other vendors, whose inventory stays the same until someone levels up, or else an hour passes, the crafting ingredients vendor's stock refreshes every time you trade with them, no waiting required.
These might have the maximum quality item limited by player level, BUT there is no minimum quality level, even in the end-game, low-level versions of ingredients can still be found at the vendor.
Why? Many of the crafting recipes depend on items which are exceptionally rare or hard to come by for no reason.
For example, the "Peace of Mind" scrolls require Crab Claws as an ingredient. There are a total of two (2) crabs in the entire game, and you cannot obtain claws anywhere else.
After a certain point, basic Elemental Essences stop spawning and only High Quality and later Alien Elemental Essences start spawning, also meaning you can't make the items requiring the low-quality item.
The rapid refreshing of the vendor can make the vendor act like a gold sink for players, and make crafting more useful.