My own experience is that there was enough ambiguity in what we needed to build. Take building a CDN for instance, what tech stack would you use? How would you deploy them? What's your caching strategy? How would you partner with ISPs? What kind of hardware would you use? A large company may spend months approving every single such decision.
In the places I've worked, the product is poorly defined. Not because we've neglected to define it, but because it's novel and amorphous and nobody knows what it should be, let alone what it will be.
Netflix on the other hand, in my view, has a clear goal: get video onto screens as efficiently as possible. It becomes much more of a pure technology problem solving situation.
Of course, I won't assume there aren't ongoing product development tasks constantly. I'm sure there's a massive back office suite, along with ads, etc.
But the overwhelming majority of the Netflix product "mandate" is pretty solid, so you don't need to spend a lot of time making sure folks are on the same page, or am I way off?