When the world was shattered much magic was lost. Even before the shattering many of the most knowledgeable mages died in the wars and chaos. A handful of universities survived. However, Runecrafting was something that even the most basic hedgewizard could do. Fragments and whole tomes about the Unknowable language were kept in libraries and even in the small villages, often the blacksmiths or other craftsmen who added basic enchantment to their wares.
Necessity being the mother of invention and the loss of so much brought a new type of enchanter to the world. One that combined innovation and scarcity with reliable magic. With the invention of Skyships these new runecrafters met up and begun to pool their knowledge and talents. Soon with an almost monopoly on cross island travel (at least for all but the richest who had access to teleportation magics… and boy do those guys gouge prices) they build up the resources and influence to advance their craft in new and varied ways.
Now most magic the average person sees are runecrafted items made by technomancers. And of course the Angels of the Isles.