>Slave implies they do what Google wants them to do, which is demonstrably not the case.

Google wants Google to be the default search engine of Mozilla's browser Firefox, Google in order to incentivize them to do it, offers them $450 million and Mozilla accepts it because otherwise they would be on the verge of bankruptcy since 80% of their revenue comes from Google. OK, they are not directly enslaved by Google but they are existentially dependent on Google in the monopolistic abuse of power situation.