If Chrome didn't have Google backing it and Apple didn't mandate Safari, Firefox would likely have significant market share.
This isn't a battle over functionality, it's monopolistic invasion of an open ecosystem by giants that control all of the ingress points. They're turning the entirety of the web itself into an ad/product funnel for giants.
I don't care if Mozilla wins. I just don't think the world is healthy with two OS/mobile/search vendors controlling every major piece of technology.
The technology sector will be healthier if these companies are forced to break up. There will be more competition and more innovation as less is spent fighting for the last 1% of growth.
Unfortunately for the Mozilla fanbois, though, Firefox won't be an usurper a second time because as already mentioned it's degenerated into simply a Chrome ripoff.
A new competitor can usurp the throne, but it needs to be a genuinely better product to do that and Firefox today is not a genuinely better product.
Then I used chrome because it was faster and performed better.
Now I use safari because its fast enough and chrome is getting creepy.
That's basically how most people 'choose' their browser.
It also goes over how every other browser engine is actually a Chrome ripoff - some UX changes don't make that so.
Remember that they are non-technical, they aren't aware of FOSS or the history of Mozilla and have no ideological reason to pick Firefox, so the decision has to be made purely on functionality.
What groundbreaking, relevant-to-the-average-user functionality (dev tools and advanced, off-by-default privacy options don't count) does Firefox have out of the box that Chrome doesn't?