Indeed, Beth did a nice job in the caves, forts, dungeons in SKyrim. I NEVER went inside the caves in Oblivion unless it was from a mod. They were all boring..Im talking about the vanilla caves.
I think the is a very wide diversity of dungeons in oblivion. It seems to me that say they are all the same is just demonstrably wrong. Some are huge and cavernous, some have tiny winding tunnels, some are linear, some are mazes, some required very odd traversal patterns (like needed to go from zone 1 to 2 back to zone 1 and then 3) vs the linear Skyrim dungeons, lakes and waterfalls and forests in Oblivion dungeons, odd things like ships or classrooms in dungeons, caves in Forts, Forts in caves, Aylied Ruins in caves, Caves in Aylied ruins, lots of backstories, some unique items, etc, etc, etc.
So the premise that Oblivion caves are boring and all the same just doesn't factually hold up.
It appears the origin of this persistent myth appears in the above quote. If you are a person that
"I NEVER went inside the caves...They were all boring" then of course you won't see the diversity - it just follows. If you believe they are all the same and then don't look, well I guess you'll always believe that.
Skyrim dungeon layouts seem smaller and more linear by comparison, but there generally tend to be more extensive backstories.