The first three things are, in this order: collaborative editing, collaborative editing, collaborative editing. Seriously, this cannot be understated.

Then: The LaTeX distribution is always up-to-date; you can run it on limited resources; it has an endless supply of conference and journal templates (so you don't have to scavenge them yourself off a random conference/publisher website); Git backend means a) you can work offline and b) version control comes in for free. These just off the top of my head.