Google's been paying Mozilla for search traffic for more than 20 years, just like the other major browsers. It's not out of kindness any more than paying Apple for Safari traffic is out of kindness. It's literally payments for search traffic and reported to the IRS by Google as "traffic acquisition cost" or TAC. Google doesn't do it for "keeping Firefox afloat," it's about Google grabbing even more search traffic and dissuading browsers from sending their traffic to alternatives, or creating their own search engines, and always has been.

But Google was a mostly reasonable partner to browser makers until they got into the business themselves. After Chrome shipped, Google properties started mysteriously becoming slower or broken in Firefox in ways that had no good technical support and that consistently siphoned large numbers of Firefox user over to Chrome before being addressed. It happened over and over on major Google properties like Gmail and Docs all through the 2010s. Jonath's Twitter thread is gone but the reporting isn't https://www.zdnet.com/article/former-mozilla-exec-google-has...

And they did it to IE and Edge too, until MS finally capitulated and jumped on Google's tech to escape the sabotaging. There's reporting on that too https://www.neowin.net/news/former-edge-intern-says-google-s...

Afloat like Weekend at Bernie's. I lived through multiple efforts to prop up the corpse while making sure it would never ever be as good as Chrome.