If magic is linked to intelligence, then it's something that basically anyone can learn (at least acquire a working knowledge of) with enough time, effort and a decent educational infrastructure, right? And presumably like anything it's something you need to start learning from a really young age to get a good knowledge of.
So, why aren't there more things like "wizard kindergarten", "pre-school for sorcerors"? Why isn't "breaking reality with your brain 101" a compulsory course in schools of any topic or level right up there with literacy and numeracy?
Think about it, a more empowered (literally) workforce is a more productive workforce. As soon as your fantasy setting hits the point where you can meet nutrient needs of large populations with relatively light agriculture (i.e. you get potatoes), why can't everyone start getting basic wizardy?
Again, not saying everyone needs to be PHENOMENAL MASTERS OF THE ARCANE!!! but, like, wouldn't everyone's lives be enriched by fucking cantrips?