I know, it's one of those threads.

But I'm asking because it doesn't seem so cut and dry.

In both games, there is a flaw.

In Oblivion, sound doesn't play a big role in being detected. You can shoot an arrow or spell right next to the enemy and he won't start searching for your character.

In Skyrim, lighting is irrelevant. The enemy won't have greater chances of detecting you when you're sneaking in broad daylight.

Although not as detailed as Skyrim, noise you create is still an essential factor on deciding if you're being detected or not.

Light is very much a factor in Skyrim. Any light source, including your own spells, can make you easier to detect.
You can only remain undetected in the daylight if your Sneak is very high.