It’s no secret that Google has a very large influence. They have influenced web pages into being highly optimized for high search engine rankings, and have pushed AMP: https://www.eff.org/deeplinks/2020/07/googles-amp-canonical-web-and-importance-web-standards-0. However I haven’t found any concrete examples of Google pushing web standards that have been adopted and require browser support. I’ve read comments here and there like this one, that the Shadow DOM was created and pushed by Google, perhaps to make it harder to block ads, but didn’t find any sources on that.
WebRTC isn’t necessarily a bad specification.
But that history shows how they draft a specification, implement a service around it at a fast pace (in this case even with a takeover), and many years later the draft turns into a än official specification.
Other browsers have no choice but to fall in line behind the draft if they want to stay relevant. And they did.
IE did the same shit with their marquee-tag back in the day. Last I checked it still works on Firefox. (It’s still not in any w3c specification)