Metal gear was supposed to be the best Story driven game this year. Fallout was supposed to be right behind it. The only one I feel did a good job of being a great game with a great story was The Witcher 3. If you told me last year I'd think a Witcher game would be higher on my list than entries from kojima and bethesda, I'd have asked you to lay off the drugs.
Fallout games have never been particularly story-driven. The main character speaks in
Fallout 4, but the story isn't really any deeper than it has been in the other entries. Because they're sandboxes, the elegance of the
Fallout games (especially
Fallout 3 onwards) is that they manage tell hundreds of small stories using very limited exposition. The stories that play out amongst the world's pre-war and post-war inhabitants
via small things like terminal entries and holotapes and diaries and object placement are pretty eloquent at times, painting a broad picture with very little. There are so many unmarked, non-quest related stories that you can find in the
Fallout games that are really clever, short-stories and I think they more than make up for the lack of a central storyline because they make the world feel very, very alive. The post-
Fallout 3 games certainly wouldn't work without them, because they're a large part of what makes exploring the wasteland entertaining and interesting.
But yeah, expecting the game to be story-driven as far as the central plot goes? That's never been the case nor the intention. It's a sandbox, it's much more about world-building than the central plot.