(×_×) We need a modular, open source browser engine desperately; one not beholden to Google or any other for profit entity. The Servo people are trying, but the task is enormous. I don't know what can be done (｡•́︿•̀｡)
On the other hand, it could well become the de-facto standard browser for embedded applications, though. The browser frame can be ported to different UI frameworks quite easily and the code has practically no dependencies outside the project itself.
Also Chromium is there, it's open enough to be a base for Chrome, Brave, Edge, and probably a few more, and it's open source, forkable at any moment Google adds something unpatchably bad. (of course independent implementations are welcome, but the ultimate goal is a healthier web through user freedom, and that doesn't necessitate Firefox directly, a ChromiumFox would be just as perfect)
Last I heard it only borrows Windows 95's aesthetics and nothing more.