It's not an apple to apple comparison since u are comparing multiplatform game to first party exclusives. First party exclusives will look better than multiplats.
Secondly u are comparing a late gen game to a early in game gen. Late gen multiplatbwill always look better as devs had more time to learn the machines.
Now a better comparisons would be last gen dragon age to xbox one and ps4 version of it. You would have noticed a massive difference in texture quality, shadows, performance, fov, lighting and so on.
Remember ps4 and xbox one were not that powerful as it came with shitty cpu.
Another comparison would be xbox one x version of rdr 2 vs xbox one version of rdr2. Xbox one x version is a significant upgrade in all areas including textures, Res, performance, shadow, lighting and so on.
Another example would be shadow of the shadow of the tomb raider game. Xbox one x version of the game provided a significant upgrade then compared to xbox one version.
Another example is halo 5. Halo5 on xbox one x provided the biggest upgrade then other x enhanced games and kept it at 4k locked 60fps which was impressive.
Like I said its probably first party games will have engines that are highs scalable and they would make it form ground up for series x first and then scale down to xbox one.
If that's true then how come cross-gen titles have always been so underwhelming, especially compared to the games that skip previous gen?
Just compare Dragon Age Inquisition to something like RDR2, for example.
Or Killzone Shadowfall