I don’t know the reason why they use Google analytics, but I think I read there was certain mitigations in place. I personally wouldn’t go there.
Google pay the most money for default search. Firefox used to have yahoo as the default search engine and could easily switch to Bing if they pay the most. Going with the most money you can get for funding the development of your browser is just sensible strategy. Firefox aren’t in the search market. Who, who cares about privacy doesn’t change their default search engine? You have yet to back up your insinuation that the default search money influences anything. I very much doubt you’ll produce anything substantial.
Considering Brave is modified Chromium, I cannot take seriously the suggestion that Firefox has more google. If Google pull the updates to chromium, Brave is dead, as they sure ain’t investing much time into building a browser. They’re more focussed on ads, and from what I’ve read, affiliate links.
You can question my knowledge base all you want. I have concerns about your motives and conclusions. I am not going to change the decision on this.