What really strikes me is why more people aren't pushing for open-source browsers. One would think that it is important to have an element of trust for something that makes up the bulk of your computer's uptime, but perhaps open source is no longer a good indicator of trust for projects as large and complex as modern browsers, or people are willing to trust them anyway.
Other than Firefox and Brave, I can't think of any "mainstream" browser choices that can be considered free software or open source.