In fact, history has shown the opposite to be true.
Take Facebook itself for example, it succeeded, not because it poured Billions into building its social network. Mark built something small, for a small market. Reached a monopoly quickly, then expanded to the next market. One after the other.
Google, Apple, Airbnb, Stripe, none became the giants they are because they spent billions on a grand vision.
Even if you look at established companies like Apple, and how they launched their first iPhone.
I've worked with tons of startups, helping them with UI/UX design. So usually in their early stages and get to see how they go from prototype to success or failure. [2]
Can 100% confirm that YC's advice of building something small for a small audience and then slowly grow that is the best advice to increase your chances of success.
Facebook should know this.
So I understand it's my observation vs Billions of dollars and a lot of very smart people who're working on it.
But History says this won't work.
[1] https://techcrunch.com/2020/04/22/magic-leap-announces-layof...