This has gotten some attention, especially about a week ago, but I really hope more people will continue to try it and, if interested, support it. It is Firefox, but heavily modified to please a different audience that prefers a slightly different UI than Firefox. It has some of the appeal of Arc, Vivaldi, and the Sidebery extension.
In my view, it is very promising, and all competition in this space is good. Here it is on Github, also.
I know, but that means it needs to keep its firefox source version up to date to keep up with security, and as its source diverges more and more from vanilla firefox, it’ll get harder to do that.
Plus they’ve already proved to be amateurs by enabling some things that really shouldn’t have been enabled: https://github.com/zen-browser/desktop/pull/927.