Oh ok, I'm sorry I must've imagined Cow levels
Dood, Diablo 2, have you really played it, there's tons of char customization
No Item customization Isn't technically the same as item content, It's a sub feature of the item content, which in its self is content. Wait a second, now you're saying items are content, but you just said, items are not content
Skills are indeed a form of content, and unless the char developement systems are literally nothing even remotely close to the other Elder scroll games, It's a given D2 has more.
Yes, those are forms of content as well, but there are many forms of content, not just those.
Since you just want to write off content, because they're different forms of content then what is available in a Elder scroll game, Let's go with Galactic civ 2 then, the content is far easier to compare the two game.
New areas, infinity, you can design your own ships if you want, there's a ton of campaign modes, there's a whole slew of ways you can go about playing the game, difficulty settings, map size, hell there are tons of settings to create a map, you can even fully customize it manually if you want, there's 8(or was it 9, well anyway there is a lot) races, and you can make a custom race if you choose. There are multiple conditions for winning(which you can disable whatever if you choose), ect.
Does that fit your requirement for what counts as content.
Lol I didn't even mention all the technologies(which is compareble to a skill tree system), that you can learn, which acording to you, doesn't count as content.