My understanding (at least where Google is concerned) is that it's a jungle situation and there's a lot of team-hopping and connection-making until you find a place to land for awhile. That may be where R&V comes into the picture, maybe some people are able to negotiate a less stressful First Act, and possibly most likely, maybe my understanding is out of date.

Remember, with the kinds of education people have at these companies coupled with the amounts of money they are receiving, "the bullied become the bullies" is a serious occupational hazard.

YMMV. From what I hear from my Googler friends, It's all about the team/manager/project you land.

Usually a good manager can spot pitfall projects from a mile away and put you on a good path to a promotion. But only being good is not enough, you have to work on the right projects, have the right results and the right visibility. If those variables are not there you may go through a downward spiral that ends up in a PIP.

My experience is that it can be pretty chill if you're happy with your level, but if you're going for a promo you need to work super hard

You are misinformed if you think Facebook is a rest and vest company. Google and Microsoft maybe.

Why would they? The point of the question is to see your thinking / problem solving process.

It's like asking why you should write a resume when you won't resumes as part of your job. It serves a similar purpose of trying to get to know who you are.