Google doesn't open a 500-engineer research lab in Grand Rapids, MI because there are not 500 Google-caliber engineers already living in Grand Rapids, MI. This is not a statement about the average talent there, but simply that the starting pool is not sufficiently large; hence the need to build offices in high density urban areas.
Google doesn't open an office in Denver so that Bay Area engineers have a slightly cheaper place to work, they do it to tap into the talent of folks who already live there.
Edit: I am basing these claims off of my own experience. I work at a satellite office of one of the big tech co's, and the vast majority of my coworkers are people who are either fresh out of a local university, or already lived here for many years before joining the company.
Google doesn't open an office in Denver so that Bay Area engineers have a slightly cheaper place to work, they do it to tap into the talent of folks who already live there.
Edit: I am basing these claims off of my own experience. I work at a satellite office of one of the big tech co's, and the vast majority of my coworkers are people who are either fresh out of a local university, or already lived here for many years before joining the company.