It is a fun little passive gold / material income. Once you have transmutagens and the ability to create mats in each of the three colors… they create more transmutagens than you use (albeit in different colors) each time you perform a craft. So once you are set up and have some points in each, you will infinitely “create” approximately 12-20 materials each day for no ongoing cost.
It is a step up from last xpac where the transmutes were all completely useless from what I remember.