It's a two horse race, and its Chrome vs Safari. Firefox is non-existent in this race and is so behind that Google pays hundreds of millions to its creator Mozilla, which contributes a significant amount to their entire revenue source.
I hate to be the one to bring in 'the facts' but Firefox itself is becoming more irrelevant and there is no question on that. Microsoft Edge (using Chromium) is used more than Firefox [0] and global Firefox usage has been declining ever since. [1]
As I said before [2] the Chrome ecosystem has given Google the dominance of more than just the web standards and the web developers were happy to live with this.
I'd say the so called 'open web' just exchanged from one behemoth to another.
To Downvoters: So 'Firefox is the most used and dominant browser and Chrome is in second place'? So 'Google is not paying Firefox in the millions'? I strongly disagree and can confidently say that Firefox usage is dying. Change my mind.
I have just given credible sources to substantiate my claims yet no counter arguments or disproving the facts are presented towards my comment.
[0] https://www.techradar.com/news/microsoft-edge-just-left-a-se...
[1] https://gs.statcounter.com/browser-market-share/desktop-mobi...
[2] https://news.ycombinator.com/item?id=27769206