Hot take: Google keeps Mozilla/Firefox alive through the default search engine placement (which makes Mozilla millions each year) so they don't get designated as a monopoly with their browser.
That's lukewarm at most, doubt you'll find many people disagreeing here!
That's not a hot take, that's just factual.
And of course they're doing the same for Apple/Safari, which wouldn't survive without the $20 million default search engine placement deal.