I’m surprised nobody has mentioned an arbitrage sort of approach to starting a business. If you work at a FANG in the US, why not hire developers in another part of the world to build out your vision for you?
Rubbish. You need an idea and to start validating it, learning and iterating, with feedback from your customers.
It's surprising how poorly the Eric Ries mentality applies in practice to the top success stories of the Valley. How many pre-validated customers wanted the Apple I (a hodgepodge circuit board)? Who would've told you they needed to use something like Facebook? Who needs an "operating system" for a niche "personal" computer? Starting a top tech company by definition can't be formulaic. It's more about the vision -- and only people with better "eyesight" can see and realize the future.