Most of the complexity we're talking about didnt come from attributes anyway, which is what your saying. Attributes and perks are not mutually exclusive, and over half the perks are just "arbitrary statistics" you talk about, since all they are, are number variables. Some add new mechanics and features. But nobody ever said Perks and attributes should be exclusive anyway. They weren't in Oblivion (non chosen perks). That's not the depth we are talking about though. Although some effects from attributes that are not present in Skyrim are missed.
We've posted many valid points on what features should be added back for more depth and gameplay styles, choices, what have you. We've made observation on what has been simplified, or in the rare case, made more complex.
There was so much flaming going on in this thread so I only dug up one post that stood out with clear points on what got dumbed down, and it was from you as a plus so let us discuss it in civilized manner.
Auto Health regen... Its auto. Hell, Morrowind didnt even have auto Magicka regen. Imagine that Atronach Birthstone Oblivion lovers. This is made even more redundant since there's still traditional wait healing.
No more degradation at all. One less thing to worry about.
The whole attribute system simplification.
Removing Spell Creation because it was "too spread sheety". Whether that why they really got rid of it, or not, is beside the point. The fact that Todd would even say that about the mechanic is ridiculous.
The whole PR campaign by Beth almost.
More cut features and mechanics.
A lot of the niche feature and mechanics even got gimped, like Vampires not even taking sun damage anymore.
That's just off the top of my head.
Auto health/magicka regen... well, with the 'wait' feature that's usable anywhere, it would be pretty easy to bypass removal of health/magicka regen by simply spamming 'wait', so could you explain more on how this would add meaningful complexity to the game?
Degradation, I can see some point as a source of gold sink, but still bit iffy since it's way too trivial with fast travel to town.
Attribute is in the game in form of "Magicka vs health vs stamina", but I do see the potential of it expanding for more meaningful character customization. But the important question is, did it really function as meaningful, complex mechanic in Morrowind and Oblivion? It's been a while since I played Morrowind, but my memory of Oblivion was that scaling was so broken in vanilla that it really didn't matter what the hell I did in leveling.
Spell wise, I agree, anything is better than this "spam expert spell of your choice to infinity".
Not sure how PR campaign adds or subtract game mechanics.
Vampirism is uninspiring in this game so yes that's another one.
The rest is little too vague so if you could elaborate I would appreciate it.