While I agree that TW3 is far from perfect, I did find it to be a much better game overall than Dragon Age: Inquisition. A large part of that was the design of side quests in The Witcher 3, the majority of which were as rich in story and interesting characters as the main quests. That element was what I had found was most missing from DA:I. The main quests in DA:I were great, but more often than not I was bored while completing side content, which wasn't an experience I had with TW3.
No doubt there are some Witcher or CD Projekt Red fans who would have proclaimed TW3 the superior game no matter how it turned out, just as there are Bioware/DA fans here who will rant about the Witcher series being terrible while simultaneously admitting to not having played it. I'm not sure however that the fanboys in either camp are representative of the majority of gamers who enjoyed either series.
I've got no particularly loyalty to any particular game developer and don't understand those who give blind loyalty to companies they don't work for. None of them send me a paycheck and I pay them for their products. I'm just a fan of a good RPG, regardless of who churns it out. On that note I thought Dragon Age: Origins was much better game than the first Witcher, which I thought was mostly terrible.
Getting back on topic...
If there is one thing about ME:A that I'd like to see similar to The Witcher 3, it would be well executed side quests that are often as rich in story as the main quests, populated with interesting characters, and some that occasionally present the player character with tough choices. I'd also like to see a return to a cinematic focus when the player character engages in dialogue with NPCs. I think dropping the cinematic conversations was one of the elements that made DA:I's side content feel less immersive than similar content in DA:O or DA2.