You aren't saying it, but it is implied or can easily misread as such. But Google is not directly funding Mozilla.
Mozilla gets its funds from many places, and one of them is Google; paying for being the default search engine. It's by far the largest amount. But not the only, nor a direct funding.
Being paid directly for a service by a company (Google paying for the privilege of being the default) is to be directly funded by that company. You're right that it's not the only source of revenue, but it's absolutely a direct source of funding.
They owe you a box of crackers. Once you've departed with it, they're no longer beholden to you.
Mitchell got Google to pay nearly double what Yahoo was willing to pay and has gotten Google to pay more each year for a dwindling user base.
If someone was going to Walmart and paying millions for a box of crackers, you’d be right in assuming the transaction wasn’t about the crackers.
That's still "just" a B2B relation and not "that one company is funding is".
Now, I'm not arguing about how good this situation is (it's bad, for a startup it's actually worse) just that it's not "funding".
Without Google funding, Mozilla wouldn't be able to maintain its operations. That is more than enough to treat the "Mozilla is funded by Google" statement as objectively true.
It's a bit of an odd market, since there aren't that many buyers or sellers, and since Firefox users are about the least valuable user segment. But that should already be reflected in the money Firefox is making from Google. And just back of the envelope it doesn't look like Google is overpaying Firefox compared to other browsers where they buy being the default search engine. We know from the recent lawsuit that Google paid Apple $26B in 2021. We also know from Mozilla's financials that the Firefox deal pays only about $400M/year.
Microsoft should definitely be interested in this, based on the statements their execs made under oath about the value of economies of scale and of query/click streams just last year. DuckDuckGo is already more than happy to pay Apple for being a non-default search (i.e. they pay Apple, and rather that complain about it being unfair they tried to keep it secret). There's no reason why Firefox couldn't get in on that action too.
We can try to justify one way or another but that's just the current reality.
It means Google doesn't actually get to say how Mozilla runs Firefox. They have a contract for a service ("make us the default search for the next N years, and we'll pay you X% revenue share on those searches"), Mozilla fulfills their part of that contract, and that's it. Google can't, for example, demand that Firefox must support some web standard proposal as a condition of being paid. If they tried making such demands, Mozilla would just sell their service to somebody not making such unreasonable demands.
And the reason people keep parrotting this idea on HN is to imply that there is some kind of wrongdoing and malicious use of funding as leverage going on. But that idea only works if this isn't a normal commerical arrangement with multiple potential bidders.
Another way it matters is that the utterly moronic ideas people throw around for this being an antitrust figleaf. Paying for default search engine placement is just how that business works, and worked before Chrome even existed.
They don't need to demand that, but how would you explain that Mozilla (despite all their talk about privacy and safety in the Internet) never considered putting an ad-blocker in the default install?
The point is: Mozilla needs funding from any of the Big Tech more than any of the Big Tech need Mozilla. They have, for all intents and purposes, sold out to the highest bidder and it doesn't matter who it is.