The difference is that Mozilla is directly and significantly funded by its biggest competitor, yet its venerated Firefox browser barely has a 2% market share.
(Which leads me to a ponderous question: if I had the wherewithal to pour hundreds of millions of dollars of my money into a non-Chromium FOSS browser, supported by 1700+ staff and 1000+ volunteers, would that browser have merely a ~2.17% market share? Hmmm... As a comparative analogy, Samsung Internet browser has barely had any improvements in years and it is surviving due to it being the default browser on the millions of Samsung smartphones & tablets worldwide, but its market share is ~1.86%. I don't think Samsung is spending half a billion a year keeping this browser alive, nor paying its browser departmental heads millions of dollars to keep the browsing chugging along.)
Since it is evident that Mozilla is a for-profit organisation funded by its biggest competitor, then we must wonder: do the Mozilla volunteers get their fair share of all that profit? If not, why not?
But since we all know Mozilla is always crying for more money, then where are the hundreds of millions of revenue going every year? I suspect it is neither going deep for improvements to the Firefox browser (I mean, come on! "tab groups" are relatively new feature in Firefox, but Firefox users have been demanding this feature for years, and Firefox's major rivals have had tab grouping feature for years, so what took Firefox so long to to do this bare needful?!), or to the many hardworking volunteers doing their best for a supposedly good (but losing) cause (Firefox's market share is eroding, and I assume Google is not sad about that trend).