The most dense cities in the world: Hong Kong, Singapore, Tokyo even New York City should be the go to locations for tech, but they're not.

The Bay Area has two things going for it that will make it hard to replace.

1. Non-competes are unenforceable. This means that the most talented engineers like working here because they can job hop with ease where in other locales they are locked into jobs working for lousy bosses.

2. Many of the most talented venture capitalists and seed investors like living here. They like it because it's pretty, you can escape the city in no time and be in nature and it's low density. I doubt the kind of people who live in Atherton or Woodside would pick up and move so easily to L.A or Manhattan. The Bay Area with its geographical boundaries provides a pretty good integration of ultra-rich neighborhoods with the middle class workers that make up the bulk of tech's working class.