So I'd say desynth is useful if you're a crafter for very specific things, but not worth the cost to level very high at the moment, there's really not much to get out of end game desynth sadly, I hope 5.
After opening the skill, any craft class that reaches 30 will automatically gain the desynthesis option. The more you fear the wrath of RNGesus, the longer you should continue with a given item before swapping to the next.
I can try again when my skill has increased. Culinarian is probably the most unique and at the same time the cheapest example.
Desynthesis seems like one of SE's failures that they don't just want to delete because it would make people who leveled it mad. GSM GSM is one of the easier desynth classes to level early on, and has multiple decent ways to obtain all demimateria.
Fieldcraft demimateria are used for making crafting and gathering gear, furniture, and many in-demand glamour items. If an item consists of 3 units of the same material you have a chance of getting 1, 2 or 3 pieces of that material.
Desytnhesis is the main source of demimateria in FFXIV, but there are some kinds that can be acquired from other sources. They not only influence the combat power of different jobs, but also the in-game economy.
Battlecraft demimateria are used to fashion weapons and battle gear, and are often used in batches of anywhere from three to ten per piece.
Okay, got it. She sells wedding clothes, among other things.