Fennec is a good alternative.

Github shows the same: Last commit 5 months ago. Funnily enough, the main dev's last comment was "Nobody quit anything" right after never showing up again.

Uazo, a collaborator of the project, seems to try to bring the project back alive. Even the /e/ Foundation is looking to support his work in order to keep bromite going.

For the future: if possible, consider the bus factor when choosing software:

What happens if <Developer> gets hit by a bus?

I had the same issue recently, since sometimes you need a chromium-based browser. After some research, I decided to opt for Mulch. It is available on F-Droid through DivestOS repo just as Mull (my main browser).

I am pretty sure the app got abandoned. If you want a nice Chromium based browser I would highly recommend you check out Vivaldi. Their recent interview with Techlore also made me feel much better about them. While I know that Brave is an option, I personally can't bring myself to trust an ad driven for profit company to run my browser. But if you can trust Brave then that is also another great option.

There is someone who has been keeping a fork of it alive: https://github.com/uazo/bromite-buildtools