I just very recently completed an almost-full set of glass armor (higher tier light armor). The only thing that isn't glass is the helmet, which is elven (next best thing)
Now, how did I get all this stuff?
I decided to join the fighter's guild a bit late in my playthrough, (level 20) and one of the first mission was to handle a bunch of burglars who were stealing from some shop owner (which is based if you ask me, this game's universe feels like a Liberty Hangout staff member's wet dream but that's material for another post).
So I spend the night in his shop, and went the loading screen fades away, what do I see? Three peons wearing fucking glass and Elven armor sneaking around behind one another. Absurd. Their leader was the one who had the Elven helmet, with the horns and all. Later in the quest you learn that these guys were ex employees from shop owner. They were probably stealing from him because they were poor. Explain to how in the hell does it make sense that three piss poor burglars are wearing the best set of standard armor in the game.
The reason behind this is that the overall level of the game scales along with the player. This is made so that the game is always a challenge to the player, but never too hard to beat. It's a game mechanic choice, and a bad one if you ask me. Which is probably the reason Skyrim works differently, thank god. The whole purpose of games like Oblivion is that you start off weak, grind yourself to higher and higher levels and then start to feel more and more powerful, unlock more effective gear and so on. How am I supposed to feel powerful when a simple shitty goblin from a beginner level quest can potentially kill me if I'm not careful enough, even if I'm wearing good tier armor after 50 hours playing? And even if they don't kill me, they'll still be a pain in the ass to slay because they will have so much HP, and the only way for me to kill them fast is to use my magical equipment, which will deplete it's charge, which will cost a small fortune to recharge. Also spells suck.
I'm so looking forward to moving onto Skyrim.