https://www.bloomberg.com/news/newsletters/2023-05-05/why-google-keeps-paying-mozilla-s-firefox-even-as-chrome-dominates

“One thing Mozilla does have going for it is a lot of money—more than $1 billion in cash reserves, according to its latest financial statement. The primary source of this capital is Google, which pays Mozilla to be the default search engine on the Firefox home page. Those payments, which started in 2005, have been increasing—up 50% over the past decade, to more than $450 million, even as the total number of Firefox users has plummeted. In 2021 these payments accounted for 83% of Mozilla’s revenue.”

https://assets.mozilla.net/annualreport/2021/mozilla-fdn-2021-fs-final-1010.pdf