I will take the companion quests, the judgements, the astrariums, the discoveries of notes, ruins, and objects, the customization of Skyhold and my character, and the war table missions.
Given that out of everything you described companion quests are the only thing that can even possibly be argued as been done better in DA:I, I'm not really impressed by your comparison.
Companion quests: You have quite a few quests you do for your friends / companions in TW3, many of those quests are longer and arguably more meaningful than the average DA:I companion quest.
Judgements: Meh. Aside from the funny parts I didn't really care about it.
Astrariums: ... Is this really supposed to be something DA:I did better than TW3?... Seriously?
Notes, ruins, objects: There are actually some very interesting examples of exploration of ancient ruins in TW3. More things of this nature were added in the latest expansion. But yes, I would agree that generally, Dragon Age games go deeper into the Lore than TW, which is a real shame because the world of TW is no less interesting IMO.
Customization of Skyhold: You mean perhaps the parts that ended up being cut from the game?
Because as far as I remember, the upgrades are linear and are barely noticed even after the fact.
War table: It was mildly interesting. Very few missions really caught my attention. Certainly nothing to write home about.
Customization of character: Admittedly I would have liked the option to play the Witcher game as one of a few completely different archetypes of characters - like Mage, Witcher, fighter, Alchemist, Druid, Archer, but I'm not really feeling too let down by the inability to do so.
The game held its own beautifully as it is, and in a way the limitations of character allowed for the game to react much more naturally to your character and choices, despite having RPG elements.