As others have said, RNG is not even remotely adding challenge. There's no skill involved in beating it. You just have to get lucky.

There's also nothing truly challenging about crafting in a game where you can have things like crafting macros. If you want a truly challenging system, you want something like EQII that had events you had to react to that could completely tank your craft if you didn't do them right. There was no macroing there because you had to stay active and engaged the entire time.

All they've done is removed the frustrating and pointless RNG.