I think English is definitely a reason that I took for granted. To add to that from my experience:

- The culture is, I think, the root of the flywheel. The entrepreneurship and competitive intensity is unlike anywhere else I've lived (not an American). It's okay to go bankrupt. It's okay to fail multiple times and burn millions in VC money, in fact it's encouraged! Take a break and raise another round and go again, VCs like second time founders. In my home country having one business go under is the worst thing imaginable.

- The capital markets, even YC (one of the lower tier accelerators by now) gives you 500k for 7%, sometimes pre-revenue. That is an absurd proposition elsewhere

- Surrounding yourself with top talent raises the ceiling for what you think is possible and accelerates your career really fast. It's inspiring for me to be around so many smart and successful people.

What's your definition of "successful people"?