Comment by commoner

This proposal would not accomplish what you intend. By slowing the adoption of open web technologies, developers and users would lean more heavily on mobile apps, which are also under Google's control considering Android's huge market share.

Developers who want to level the playing field need to develop sites that fully support Firefox and other browsers that are not based on Chromium. Users who want to see a more open web need to use Firefox and non-Chromium browsers, and complain to developers who don't properly support them.