Just remember that Google is essentially an advertising company and that they were always going to squeeze this opening closed as soon as they could get away with it. I do fear for a future were even Firefox ends up caving in. Ladybird browser might be our only hope until something legal comes along to block functionality.
Firefox haven't caved in so far. Why do u think it might in future?
I'm not knocking Mozilla for taking money from Google, it was a smart move. Most users would use Google anyway, so Mozilla pocketing billions by making users preferred search engine the default didn't really hurt anyone. Some of that money should however have gone into a trust or some type of investment so that funding for browser development would be safe if the ad money ever dried up.
Maybe someone at Mozilla knows something I don't, but there doesn't seem to be much planning for the future.