"It wouldn't look that bad" is the answer you're looking for. If you haven't played the original Fallout games made by Black Isle, you might be a little surprised at the screen above. But before Bethesda got their hands on the Fallout license and transformed it into a First/Third-person Action-RPG, it was an Isometric (meaning an almost top-down view) RPG.
You'll be familiar with this view if you've played games like Diablo or League of Legends. In a way it's a really cool nod to the first games in the Fallout series. But how did this happen? It looks like reddit user yttriumtyclief was messing around with the console commands in order to take pretty screenshots until he figured out he could place the camera in that classic viewpoint.
Even though it's an awesome nod to the older games, it doesn't look like it's that useful (if you're playing Fallout 4 on PC, you can recreate the view-mode by messing with some .ini files and moving around the third-person camera). It seem to work if you try to play the full game like this either, "It falls apart once you try to enter combat though, or do really anything else besides walking around outside. It also won’t work indoors simply because of how 3D environments are created."
That sounds like a bit of a bummer, but hey, at least we got those pretty screenshots right? You can compare the first game to the new pretty screenshots below.