The other is Mozilla apologism, even more in hands of Google or WebKit apologism in hands of Apple AND Google. Google dominate Web standarts, that is a fact because of its story as reference company in Internet. It's not about browser engines, it's nowadays irrelevant which you use and certainly not the point of the Google incommings. Same as with the discussions of the end of Mv2 and everybody said that is a problem for Chromium, relaying on the Chrome Store, Certainly with Chromium 146 ends the support of Mv2, but it will sooner or later also end for all other browsers, like in 2013 the end of Mv1.

Mv3 is a new standart for extensions, which limit somewhat the amount of filters in the adblocking, but improved the privacy due a different cookie handling. In real tests the difference is irrelevant for the user (eg. Adblock Plus is currently Mv3). Also irrelevant for browsers with inbuild adblockers, whose filterlists don't depends on Google. Apart beeing a new standart means for the devs the maintance and release of two versions of their extensions, Mv2 and Mv3, to be able to stay in the stores, means also that NOBODY would support Mv2 for infinite, even not Firefox and forks, at least if they don't also include an ad/trackerblocker in the browsers with independent filterlists.

That are the facts, without Vivaldi apologism.