The value the worker provides to google doesn't vary with location. If someone wants to live in an overpriced urban area, that's their choice. Why should google have to subsidize it?

It shouldn't matter where in the United States you live, NYC, Puerto Rico, Hawaii, Guam, or some forsaken place like Indiana, etc.. If you get your work done, you should have the same responsibilities and benefits.

Salary already isn't directly proportional to value added, so I'm not sure where that idea comes from.

IMO, it affirms the "rugged individualism" mythos, and has a sprinkling of the fundamental attribution error.

Salaries are mostly controlled by market forces, opening up to remote work will result in a larger supply of potential employees, to include those who were previously not considered, but are good enough, and are willing to accept less than current Bay Area/coastal salaries.

Thinking salaries are governed by market forces is a fundamental attribution error

Then why does having simultaneous competing offers result always result in a higher salary? Typically higher than the "maximum" figure originally signaled

Pay differences are already a source of major social friction, but companies find ways to mitigate or avoid the problem. Why would this be any different?