Even if you're getting a lot of money from someone, you can still bite the hand that feeds you a bit. For example, Apple receives a lot of money from Google so that Google is the default search on iOS. The UK government has noted that Apple receives a "substantial majority" of the $1.5B Google spends to be in the default position in the UK alone. Let's assume that substantial majority is at least two-thirds of that so Google gives Apple $1B to be the iPhone's search engine in the UK every year. That's $15 for every person in the UK - including infants, people with Android phones, etc. At the same time, Apple is working hard to limit ad tracking.

Some people have estimated that Google gives Apple $15B in total for its default search position. That could mean that around 16-23% of Apple's profits come from Google paying for being the default search engine. Heck, analysts said it would probably reach $18-20B for 2022 (https://www.macrumors.com/2021/08/27/google-could-pay-apple-...). Apple's profits for the past 12 months was $94.7B (which is up around 66% against the previous 12 months). $20B would still be 21% of that. Even $15B is 16% of that.

The default search on iPhone is one of Apple's largest businesses. It's bigger than its Mac business or its iPad business or its wearables business.

Yet Apple is still biting the hand that feeds them by working against ad tracking. One can argue that it might help Apple in other ways like customer goodwill, making marketers more reliant on Apple-provided data if third parties can't track as well, weakening Google in ways that might weaken the Android ecosystem, etc. Similarly, Mozilla is trying to get a certain amount of customer goodwill and potentially finding other ways for marketers to reach their customers.

While Apple's position in the market is quite secure, Mozilla might be seeing a future where Google doesn't think it needs to pay Mozilla for that default search position. Firefox users are likely people who know how to switch browser defaults and Firefox marketshare is getting small and continuing to decline. I think that's a big reason that we're seeing Mozilla search for new sources of revenue. It looks like Firefox usage is down more than 50% over the past 5 years alone. That means its default search position is a lot less valuable. Even if Google will continue to pay, those payments are likely shrinking. Firefox's position on mobile is even worse.

Even if Mozilla is mostly financed by Google, that financing is likely shrinking. At the same time, software engineers in the US are getting really expensive and Google is pouring money into Chrome (engineers and marketing). Chrome also benefits from a lot of third parties putting money into Chrome. Microsoft is now using Chromium for Edge and Node and the rest of the JS world uses V8. That puts so much weight behind Chromium for Mozilla to fight against - while likely seeing their funding from Google shrink.

It looks like Mozilla's royalty revenue is declining a bit (probably around 10% over the past 5 years), but not too substantially so far (and there's always some noise). But it's also not growing which puts them in a bit of a precarious position given that Google and others are investing more and more in Chromium, their marketshare is declining (which will likely lead to declines in search engine payments in the future), and the increasing cost of software engineers. So do you try to stick it out with the Google search agreement knowing that your users landing on Google's website will be told to upgrade to Chrome or do you try and find a source of revenue that isn't a competitor?

Or maybe the premise that Mozilla is beholden to Google because of their income stream is false?

It seems like every other month there's a thread complaining about how Mozilla would never really do anything against Google's interests because of their income stream, and then every other month in between those rant threads Mozilla launches some new tracking protection [0] or privacy initiative directed specifically against Google.

[0] https://twitter.com/__jakub_g/status/1365400306767581185