> What would Google do if Mozilla blocks all ads browser wide by default? (Which they can't do adhoc because it is probably explitically forbidden in their contract with Google)

Just a few things:

1. Mozilla did explore this a number of years ago, concluded that

  a. if you block all ads, you break the revenue of pretty much the entire web, so that's probably not something you want;

  b. if you block all ads, you break loading of many websites, and that's not something an established browser can afford to do;

  c. if you do either, websites are just going to block your browser;

2. Mozilla actually came up with ideas for blocking all ads without breaking the web, decided that there were too many variables, too many ways to break everything by accident, and did not pursue this plan – however, as far as I can tell, Brave either reinvented the same ideas or picked up that plan.

Also, to answer your specific question, Google pre-emptively reacted against any attempt of Mozilla by launching Chrome. If you recall, they launched Chrome pretty much because they could not buy Mozilla.

> Irregardless of semantics, Mozilla is entirely dependent on the privacy invading ad system.

While we live in a world where ads = privacy invasion, this doesn't have to be the case. If you look at recent versions of Firefox and ongoing projects, Mozilla has stepped up on privacy protection and keeps doing so.

Again, it's hard to do without breaking the web. But some can be done, one step at a time, and Mozilla is working on it.

> Everyone knows that default settings matter, as around 80% of users never change much in their browsers, and it is this majority user base which forms the foundation for the contracts between browser makers and search engines.

True.