You don't remember what Fallout 3 on consoles actually looked like, and it seems like you may not understand why Fallout games look the way they do in general, given what they're doing behind the scenes. Haven't you read through any of the threads on this exact subject? it's perfectly okay to be disappointed, but it's not cool to make shit up on the spot, and this 'barely advanced graphics' stuff is just that.
Do I really need to drudge up my actual honest to god image comparison for the umpteenth time?
MGSV is a very different beast. If it was doing some of the things Fallout does (which aren't necessary for the type of game that MGSV is), it wouldn't look quite as good as it does, either. Keep in mind that Fallout's engine is tracking an entire open world of movable physics based objects and fairly intensive AI, and that the scale of interaction that the world itself boasts, brought upon by the world being populated by thousands of dynamic objects,
comes at a cost. Same reason why Fallout 3 doesn't look as good as Dragon's Dogma or Just Cause 2 or Red Dead Redemption or Mafia 2 or Forza Horizon, even though they're totally all open world!!1
That's... not really how it works?
Really...