I feel like most of Vivaldi's target audience is knowledgeable enough to enable an extension that's disabled by default. Heck, just display a notification asking whether to enable the extension when a Google Meet site is opened.
These proprietary, bundled-by-default extensions are just a taste of what a browser engine monopoly looks like. Alternative frontends to the Chromium engine don't make a difference as these frontends will suck up whatever changes upstream. We only have 3 major/relevant engines left, Blink (Chromium), Gecko (Firefox) and WebKit (Safari, originated in Konqueror I think), with Blink being a fork of WebKit (although very diverged by now).
The web is so complex now that I don't really see more engines becoming actually usable. Even Microsoft bailed out and eventually switched Edge over to Chromium.