I'm pretty sure that the vast majority of magical study is "abstracted away", which is terrible, because it would be awesome to have a stack of books and notes needed to operate your mage at full effectiveness.
This, I think, is the main problem we're running into.
It's a game, so everything is kind of abstracted away. We go to a merchant and buy a spell for a few gold and all of a sudden we can hurl fireballs or heal ourselves. Makes you wonder why everybody doesn't run out and learn some spells. And it makes all those books scattered around the mage's guild mere decoration.
The fact of the matter is that there's some study or practice or something implied in gaining skill and leveling up.
Realistically, I can't just pick up a sword and hack on a piece of wood for three weeks and become a master swordsman, but that's how it works in
Oblivion. I can't hop up and down in one place and become a master acrobat, but that's how it works in
Oblivion. And, in
Oblivion, I can cast the same crappy spell a few dozen times... Then go to a merchant and spend a few gold... And suddenly be able to hurl fiery death at my foes.
So, from a game mechanics standpoint, it doesn't seem like there's any reason a merchant wouldn't go learn a couple handy spells. Or why your guards wouldn't all be conjuring up their own Daedric armor. Or why we wouldn't all be powerful mages.
I see magic as being a lot like quantum physics or nanotechnology; the main reason it's not used by soldiers or your average citizen is because it takes years and years of effort to make effects that are only occasionally applicable to a task. Sure, you can then transform elements and strike people down with shiny death, but even then it's probably not as cost-effective to do that as it is to stab someone with a pointy metal stick.
Again, we aren't really seeing this since it's all abstracted away... But you have to imagine the kind of skill and training necessary to do stuff in the game.
So, you've got an infestation of rats in your house... How much time/effort/skill/training does it take to just set out some rat poison or traps? And how much time/effort/skill/training does it take to shoot them with a bow from across the room? Which of the two are you most likely to do to get rid of your rats?
You're a merchant and you're worried about being knifed while hauling your goods from town to town... How much time/effort/skill/training does it take to put on a chainmail shirt? How much time/effort/skill/training does it take to learn a protective spell?
Sure, you could buy a ring or enchant your belt or something... But how much will that cost, compared to a bit of chainmail? Yeah, it'd be lighter... And maybe protect better... But for how long? Would you need to remember to activate it? Would it need to be recharged periodically?
If you're just looking for a quick & dirty solution, it's generally easier to stab something with a pointy bit of metal. Or throw a heavy rock at it. Or wear a bit of armor. Or learn how to swim. Or take a boat. Or whatever.
Sure, with some practice and study and training you can learn to hurl fireballs and lightning bolts and walk on water and whatnot... But maybe your average merchant is more interested in buying and selling goods and doesn't want to spend years studying. And maybe your average merchant doesn't want to pay thousands and thousands of gold to hire a mage as a bodyguard when some hunk of meat with armor and a sword will do it for tens of gold instead.
I mean... Just because magic is omnipresent does not mean it's as easy as breathing. Maybe it is just plain simpler/easier to grab a chunk of flint than it is to magically light a fire.