Mozilla CEO Chris Beard wrote an interesting blog post in response to Microsoft adopting Chromium as the engine for their Edge browser. He makes the point that reducing the number of stakeholders among browser makes gives Google an even bigger influence with web standards bodies.
In terms of how Mozilla views itself in relation to Google:
We compete with Google not because it’s a good business opportunity. We compete with Google because the health of the internet and online life depend on competition and choice. They depend on consumers being able to decide we want something better and to take action.
I mean, Chris isn’t wrong about the first part. It’s just a bit of a shock to see it so clearly stated. That being said, Microsoft was facing a losing battle trying to push an EdgeHTML-based Edge browser on the market. Switching to Chromium allows them to better standardize web app performance, and get the benefit of Chrome’s dense extension ecosystem.
Unlike Mozilla, Microsoft has to make organizational decisions with an eye for returns to shareholders, not fighting the good fight of browser standards.