We need a cleaner path to desired runes. Random outcomes in crafting and rare drop rates make mythic crafting a largely unusable feature of the game. Being able to craft other runes is useful, but not when outcomes are completely random. Random outcomes means individual players are going to have wildly different paths to achieve their goals in terms of time spent farming and luck on the crafting. Not to mention the massive amount of wastage.
Diablo 2 had a clear path. It wasn’t necessarily an easy path, but it was a clear one. I recommend having recipes that allow players to achieve desired outcomes instead of relying on random luck.