I still like DA2 considerably more than DA:I, despite all its issues and having been pretty frustrating to play through, especially at release. I guess it's because of the more original aspects it had going for it. The companions carried the game for me, and I enjoyed the friendship/rivalry system. It was not perfectly implemented but a pretty interesting alternative to the traditional approve/disapprove, like/dislike meter.
While DA:I appears to be better received all around, I... actually find it really hard to find anything to like in it. I like the character creation, but even that is sullied by Bioware's worst attempt at hair ever. I enjoyed Blackwall's character and kinda like what I consider the other better-written characters, Solas, Vivienne and Cole. And that's about it. It was a bore to play and I actually think the writing isn't any better than in DA2. Sure, not everyone goes insane anymore, which is nice, but instead people tend to be just dumb. I used to really enjoy the romances and interactions with companions but some of DA:I's romances left me wondering whether Bioware has started trolling players with them because they tend to be made fun of.
The lifeless worlds filled with nothing but repetitive and meaningless quests have been mentioned enough. I thought it was a nice sign of showing attention to detail when Skyrim added notes and journals to its dungeons to give them a story. Then Bioware took that idea and... got it all wrong, somehow. I'm not even sure how they managed that.
I know Skyrim caused games to put more focus on the idea of open worlds and the size of their worlds, but vast spaces you're left to explore on your own still hurt the urgency of the main story. TW3's world is beautiful, it's fun to explore, but it always feels weird to roam when you're supposed to be in a hurry to find Ciri or find a way to stop the Wild Hunt. I'm doing a third playthrough at the moment and disabled the question marks on the map for the first time around, but I still tend to look up buildings and ruins on the map and head toward them to see if they contain anything interesting. I've also tried to stick as close to the quest's level requirement as I can and not wait too long to advance the Baron's and the Bog's storyline, but again that leaves me to go all the way to the swamp again once already learning that Ciri could still be in Novigrad, which is in the very opposite direction.