The soul reason that I craft is to make GIL and make my own gear to SAVE MY GIL. The challenge really falls to time management for me. Which is a piss-poor challenge for me.
Like the OP said... ARR master books were a PAIN to get, and a REAL challenge. The endgame crafting was difficult, layered, and complex. Much like a savage raid for a disciple of war/magic. Either weren't necessary to at all, but a choice none the less if I were to take on those challenges.
The OP is 100% correct that crafting is simply a joke now, and the only challenge avail at this point is the ishgard restoration titles if that's your thing. Fine. Grinding out RNG recipes for a title doesn't get my motor running honestly. Sure it's fun to participate in a community driven timed event, but that's about it. I would rather sit on a flagpole in a snowstorm then go back into the diadem to farm mats. NO!
Every crafting class being EXACTLY the same is just wrong also. ARR to Stormblood did it right for crafting. Each class is unique and varied. This made being a good crafter meant dabbling in every class. Now all you need is 12 hours to max out EVERY class, and nobody can deny the amount of omnicrafters-gathers that were minted this expansion.
This leads me to believe that SE is planning to change the crafting game in 6.0 with a completely level playing field with each class respectively. With each class literally identical with skills we can speculate on what is going to show up in 6.0.
They did it with gatherers collectibles, and I prefer the new method now. Good bye node jumping, hello simplified interface. Gathering scrips actually has some varied RNG now vs. getting a discerning eye proc being your main focus. Crafting collectables will probably see the same treatment with a whole new interface, where you NEED to pay attention to maximize your rotation. Can't just macro through scrips anymore will probably be the new crafting meta.
I for one have made a stupid amount of GIL this expansion, but have nothing to spend it on unless it's cosmetic. That's just backwards thinking for crafting and the soul reason to make gear is to make your character better. Not look like Goku.... which is fine... but just strange that glamour is the crafting end game for MAX GIL gain. You know your in trouble when BiS is cheaper then sought after glamour items. Messed up.