All the forks need to make a common engine independent of Mozilla. Pale Moon did it with Goanna and it is shared between Basilisk and K-Meleon as well. The big problem is that any new engine has to beat being filtered by Cloudflare or other WAFs that discriminate by user agent. A bold idea is for all the Firefox forks to rebase off of the new Ladybird engine and abandon the old Gecko codebase entirely.

It is obvious that Cloudflare is being influenced to enforce browser monopolies. Imagine if Cloudflare existed in 2003 and stopped non Internet Explorer browsers. If you use cloudflare to “protect” your site you are discriminating against browser choice and are as bad as Microsoft in 1998.

The closest you can get is the Seamonkey browser, which forked off the old Mozilla Application Suite that Netscape 6/7 was based on. The last version of Netscape 9 was just a rebranded Firefox 2.x.