Sorry but DAI did fail at creating a living world. most NPCs stand frozen in one spot and have no life other than standing still so the player knows where to find them at all times. I don't recall a day/night cycle so if there is one and I can't remember for sure after 190 hours it couldn't have been meaningful.
I couldn't disagree more with your opinion.
I felt the world was very much alive.
The NPCs might have been frozen, but they were standing around chatting, which is much better then the NPCs in Skyrim, who just did laps around the settlement and a day life cycle is more annoying than world building.
I liked that I could overheard conversations NPCs were having, that I run to the top of a hill and see the wild life in the field below me, I liked that each map had its own distinct feel, with its own flora and fauna. I liked that the NPCs in Skyhold changed based on your decisions and that you could see your impact on the environment around you.
That is what makes a living world to me, not NPCs doing laps or a day night cycle but seeing the world react to you and having each map have meaningful different environments.
As for the settlement differences between DA:I & TW3, who cares, DA:I was about exploring different environments, from lush forests to barren wastelands, not exploring settlements. Maybe TW3 does have more settlements but less wilderness or explore, maybe it has both, it doesn't matter since DA:I design is to be focused on the wilderness, just like DA2's design was focused on Kirkwall and making that one city feel alive.