The same thing happens with webkit.

the ordinary user will only notice it when his adblocker stops working.

Firefox maintains the largest extension market that’s not based on Chrome, and the company has said it will adopt Mv3 in the interest of cross-browser compatibility.

We all know, and more the Mozilla people, that this cross-browser compatibility is false, the big G is forcing them to use their technology unilaterally. Mozilla is one step away from switching to blink engine, but they has no more options, with the huge losses generated by many bad decisions made, especially during the disastrous management of Brendan Eich. Google became their only oxygen tank (keeping Mozilla afloat enough to avoid antitrust laws and disintegrate the conglomerate).