Butterfiles, landscape, random encounters, cities, NPCs, books that contain hints for possible quests and artifacts, crafting, ingredients, puzzles, marriage...
But you know what, fine. It is a linear, dungeon-crawler, but then might as well admit that the it's just as true for the rest of the series, because they're hardly different in this regard...
Butterflies are butterflies, landscape is not an RPG mechanic, just pretty with some more killing and looting scattered across it and a backdrop for the dungeons, random encounters are scarce flavors to add to the exploration and looting base, NPCs aren't choices or any-such, either, and simply state simple one-liners or give you quests leading to more fetching and killing without choices or consequences, books that contain those lead to artifacts and quests which lead to more fetching and killing with little choice and consequence (except the lore books... those be fun reading and as I've always done since Daggerfall, collect them all I say... EVERY SINGLE ONE), crafting is basic tool to create more things to do more killing and fetching, ingredients make potions for more killing and fetching, puzzles also add flavor to the killing and fetching, and marriage does nothing, really.
The choices and consequences... where are these? The actual content outside of the killing and fetching areas are scarcely anything time-consuming or entertaining on their own and yes, that does go for most TES games. Have I said otherwise? Did you automatically assume that because I'm criticizing Skyrim I must be excluding the rest of the series? If so, that's a grave mistake that would very easily taint what I've said with a paint that simply is not there. What doesn't go for the other games, to differing degrees depending on game, is the magnitude to which Skyrim lacks feedback or even some form of character specialization recognized by the gameworld. Dungeon-diving, rogue-like style, has always been a focus of TES.
I'm not denying that nor claiming otherwise in that regard. Skyrim does, however, lack the reputation systems, the dispositions, the build-specific (at least, when older iterations had a decent amount of content, skill requirements, or exclusiveness with proper reputation of their own) factions, or really factions in general, and certain general pieces of meaningful character customization that past games have had, which have unfortunately diminished with each iteration whether one approves or not. Choice has never been as central as I would have liked, but there were also more choices in past TES games (take, for example, Daggerfall's main questline). In any case, my criticism of Skyrim was not meant to be a criticism of Skyrim and praise for past games, just a criticism of Skyrim. Whether it applies to Arena-Oblivion or not was not a focus of my disapproval. I'm not pretending past games had something completely different from Skyrim, but at the very least, they did have some reputation systems and faction... anything beyond the small handfuls of quests that don't care what type of character the player is Skyrim has labeled as factions. Skyrim's back to Arena's level in that area.
You are not wrong at anything. You are simply stating your opinions on the game as others have done as well. btw, you stil haven't answered me, what's your favorite color?
Blue, and an opinion is whether Skyrim's design is a good thing or not, not the factual base of Skyrim's design.