This is not possible according to the usual definition of "market rate".
If Google is willing to pay X, that is the market rate.
edit - I see how my post was misleading. I should have said X is a "lower bound" for the market rate.
This puts Google in the position of being a monopsony for the labor of programmers; that is, they're the only or primary buyer of that commodity. Part of antitrust laws is preventing that, so, yes, there is a problem if a monopsony arises, but Google isn't in that position anyway because jobs aren't completely interchangeable the same way programmers aren't completely interchangeable. For example, companies can compete on the basis of not being Google, which attracts some people. Companies can compete on the basis of being based in some other geographic location, or having other things to work on, or having a different mix of salary and benefits.
Google offering the highest salary doesn't mean they automatically get everyone. It means they get people who want the highest salary to do what Google's interested in as opposed to wanting to work on some kinds of technology Google isn't pursuing.
Single-firm anticompetitive behavior, as defined by FTC: (https://www.ftc.gov/enforcement/anticompetitive-practices)
Single Firm Conduct:
"It is unlawful for a company to monopolize or attempt to monopolize trade, meaning a firm with market power cannot act to maintain or acquire a dominant position by excluding competitors or preventing new entry. It is important to note that it is not illegal for a company to have a monopoly, to charge “high prices,” or to try to achieve a monopoly position by aggressive methods. A company violates the law only if it tries to maintain or acquire a monopoly through unreasonable methods."
Horizontal Conduct:
"It is illegal for businesses to act together in ways that can limit competition, lead to higher prices, or hinder other businesses from entering the market. The FTC challenges unreasonable horizontal restraints of trade. Such agreements may be considered unreasonable when competitors interact to such a degree that they are no longer acting independently, or when collaborating gives competitors the ability to wield market power together. Certain acts are considered so harmful to competition that they are almost always illegal. These include arrangements to fix prices, divide markets, or rig bids."
Staff aren't a product or commodity.
I have a relative who bought a very nice beach house from his legal fees suing a hospital network for doing something similar.
