The examples you cite are exceptions, not the rule.
Most Google engineers still work in CA, and it's easier to get hired for a role at HQ because there are always openings for all kinds of positions. For the smaller offices, they might only be hiring infra or only hiring L6+, etc.
For movies, think about what you'd do as a young actor trying to get a major role. Would you live in Atlanta where a handful of films are shot every year, or would you live in LA where hundreds of opportunities come up every month?
Most Google engineers still work in CA, and it's easier to get hired for a role at HQ because there are always openings for all kinds of positions. For the smaller offices, they might only be hiring infra or only hiring L6+, etc.
For movies, think about what you'd do as a young actor trying to get a major role. Would you live in Atlanta where a handful of films are shot every year, or would you live in LA where hundreds of opportunities come up every month?