I'm going to advocate for Zen here. https://zen-browser.app/ I've been using it for the past year or so and love using it so far. There's some bugs here and there but nothing that occurs often or breaks my workflow. And it's based on Firefox :)
Why does their website seem like a clone of Anthropic's?
I really want to like zen but every so often it eats all my RAM. Many have reported similar issues.
https://github.com/zen-browser/desktop/issues/8932