Very important! But that doesn't mean it needs to be 4k/140fps. A game graphic style and performance is the #1 factor for immersion. It sucks to play Crysis or Kingdom Come: Deliverance at 15fps, but if I look at an ingame tree and don't identify that as a tree, it don't matter that the game is 1080p/60fps.

Okami is a perfect example of the right style for the game type, but try to use the same style on a racing-sim game, and it'll fail miserably.

Just to let you know, DA:I is selling for ~$47 at the Brazilian Xbox Store right now. You can get that price by changing your console location.