Sadly Chromium is WAYYYY easier to development on than Firefox. Had Mozilla spent effort making the base of it as a framework in the same way Chromium is, they may have considered it.
There is a reason why Electron, QT etc use Chromium.
Kind of a shame.. There are a few areas where FireFox absolutely smokes Chrome. The way it reflows some heavy DOMs interactively is almost magical in comparison.
Curious, what makes Chromium better in your opinion? I have probably just touched the surface of the dev tools on both and haven‘t used any features that I would be missing on either.
It's a blank browser, has barely any "Google" specific stuff in it ready to go. It is easy to develop for, doesn't require cross language compiling (rust/c++), builds fast, easy to understand how the different parts work (at least for a browser developer it should be), has documentation, is meant to be used to develop your own browser.
Are you sure Chromium builds fast? lol, it takes my laptop with 12 cores and 64gb of ram over an hour to compile from scratch, not counting the ~20gb of git history to download (I maintain an internal build at work).
Limiting the threads as somebody elses said. For chromium no one really builds it on a laptop, everyone in my team used a build server or a 32 core monster desktop.
They worked on it a bit [0] but it has been abandoned along with all the other embedding efforts over time. As someone who embeds Chromium (via CEF) only because it's easy, I would really appreciate (and have been shouting into the wind about) focus on the embeddability of Gecko.
There is a reason why Electron, QT etc use Chromium.