None of the browsers that exist are free of critical aspects and Vivaldi is no exception. That Google and EDGE are not interested in the Vivaldi UI is not true at all, it shows the attempt to imitate different functions introduced by Vivaldi with mediocre results. Although Vivaldi is still a minority browser, it is gaining a lot of acceptance in large companies and even in the automotive world with the inclusion of series in Renault, Polestar, Mercedes and even VAG, which not even Google has achieved, which can mean more than 40 million users in the near future. In other words, it can become a competitor to be taken seriously, as a European response to Google. From this point of view, this discrepancy of a script that differentiates Vivaldi from the others makes sense, although it does not conform to the traditional definition of OpenSource, since it is "Open" at the user level, but not to the competition for being owned by Vivaldi . Making it OpenSource, with restrictive licenses in the background, wouldn't change anything.