Changing the "Caster beats Mundane" paradigm

[LibraryOgre]

That may be true for wizardry, but in most settings that's only a tiny fraction of all spell-casting, not to mention other magic. It very well could be that they're playing in the shallow end of the pool, where the waves are small enough that the variations can be ignored or worked around.

And your setting's alterations are not the core assumptions of the various editions of D&D, where 9th level spells, some of which can do most anything, can be freely learned by anyone capable of understanding those formulae. Where wizardry can be taught in academies and classrooms. In some cases, where the earliest wizards were gods, who taught the craft to mortals who have been mucking about with it for a thousand years or more.