Let's put it this way, all browsers must include certain APIs to function and these APIs are independent of the browser engine. A bank or other official sites require these APIs and certificates for obvious security reasons. Other Google APIs, such as safe browsing, that supposedly protects against phishing sites, are also included in Firefox, but it is also from Google, although there it is called Firefox Save Browsing. With one difference, in Vivaldi I can disable it in the settings, since the adblocker filters do the same, but not in Firefox. I can also deactivate the other Google APIs there, which the devs have left in the configuration as optional use, since without them some users cannot access Google services. In Firefox they are activated yes or yes, whether you need them or not.*

But all this is not the current problem when Google manages to carry out its WEI DRM plan, this will affect any browser equally, since it has nothing to do with the engine they use. Although it is legitimate that websites can block insecure browsers without a certificate, to protect themselves, it is not legitimate when this certificate depends on the decision of a private commercial company, such as Google, which decides which browser deserves this certificate and which does not. This would only be acceptable when this certificate or token comes from an independent institution.

As an aside, although Google has long left this "Don't be evil" motto behind and uses many dirty tricks to be able to profile and track users, because it makes money from this, not all Goggle APIs have this feature, some have a pure technical function. For this reason, it is advisable not to put on a tin foil hat when choosing a browser, the greatest danger to privacy, apart from the lack of common sense, is part of the Google search engine, this is the main source of user data for this company, not the browser (that is, if it is not precisely Chrome, Edge or Opera).