BTW every time competition comes up in this case we should probably ask: competition in what? The case appears to be focusing on search engines and ad networks, but trying to create more competition in search could end up reducing competition in browsers (hence Mozilla's concern about collateral damage). Google is so huge and has so many interlocking monopolies that I don't envy anyone who's trying to fix any of it.
Even if browser competition is important, and even if that (currently) requires a stream of money to flow to Mozilla, it doesn't follow that we should allow unlawful abuse of other monopolies in order to support that. Of course, it's possible the courts decide the status quo is lawful and there's no change.
In a hypothetical situation where you separate Google Ads from Google Search from Google everything else, Google search would still want to pay browsers for default search, and Chrome, Firefox, Safari, etc would still have a revenue stream; however, they would only be able to do so to the extent of their web search revenues. Likely the baby Googles are still dominant in all of their fields, but it's not as assured, because there will be less cross promotion, exclusivity, and tying.
If you instead leave Google whole, and prohibit paying browsers for default search, you still have internal payments (de facto, if not explicit) to Chrome and Android that drive product decisions like defaults and putting an unremovable search bar in the default launcher.
