Justin Slippery Slope theory---often correct---dictates that if ad blockers go then several security extensions will go, too. Housecleaning is an ocd affair....
Or will we live in a world where the free elect Firefox king?
And Brave queen?
Taking browser security out of the hands of its users and just saying 'trust us' is a hard thing to sell, yes? Or a deliriously easy thing to sell? And why is it being sold by google?--(I don't keep up with the literature,,,,)
A very important question you asked, nonetheless.