As an overall package, Witcher 3 is more believable to me.
I think DAI looks really, really good, but the lightining is very flat. No dynamic weather and TOD system makes the world look very bland and static.
Models in DA are hit or miss. Some are amazing, others are just plain terrible. Witcher 3 is a bit more consistent, and the facil expressions are leagues better.
The grass is another story. Before the game was released I was one of the people disappointed with the grass in Witcher 3 (I still am), and claimed it was better in DA. Now, while I still think the grass does look better in DA in still shots, overall, taking into account all the foliage, trees and how they react to the wind, I think Witcher 3 ends up looking better to me.
The textures are much better in DAI, I'll give you that.
Those weren't even max textures iirc.
Witcher 3 is no slouch and the atmosphere can be fantastic and is often very good, and the grass suits the artstyle but it's mushy mang.
I wish I could run it at 4k and keep at least a proper locked 30 - so it would look more realistic and clearer. That would be something but it'd take an expensive rig. It's nice at 1440p but comes with the fps drop, especially with hotspots like abandoned village in the starting area (there area a few others and I've not explored much of it yet, but you do fight there during a quest). So I locked it to 37fps.