my 2 cents...
I think it really depends on the team, the kind of game, the budget and your position in the company
a creative director can decide a lot of stuff, but others writers are just hired to fill the gaps between action sequences with a crappy plot...
For me, the first thing is maybe a basic idea : what kind of Universe and what kind of gameplay (open world, fps, rpg elements...) are we creating. And then the design team must become the center of the development, because gameplay will/should drive narration : cut-scenes ? narration in game ? choices ? exploration ? how can you use interactivity to tell the story (through environment, through dialogues, directly within the gameplay etc). You need to thin about it and discuss it with your team
Then there should be a lot of feedback between the writer(s) and the designer(s) because if you don't consider both from the very beginning, you have 99% chances to fail. It's the same thing for the characters, the type of environment, the background etc
If you just want to write a story and hope someone will turn it into a videogame, my advise would be to write a book or a script that will turn into a huge blockbuster/best seller and then saying "who wants to make a videogame out of it ?"







