The important thing to keep in mind with this announcement is that the glacial pace was previously a restriction of being attached to SerenityOS. Everything needed to be built from scratch with no reliance on third party libraries. Now that they're detaching from Serenity they can start reaping the benefits of the existing work in the FOSS ecosystem, which should enable a faster pace of development.
now they could embed chromium LOL
I’m not sure what in the FOSS ecosystem will actually help them if they’re trying to take a fresh set of eyes on implementing a web browser.
EDIT: ga sibling comment beat me to the joke
They could also rely on existing multimedia libraries for audio/video (ffmpeg). Those are the main things that jump out to me. There's so much ground to cover that there's probably more, though. Maybe SDL for gamepad support?
Some things in other browsers could be used without much pain, e.g. image renderers, JavaScript engines. Things that are totally self contained and can be used until someone writes a suitable replacement.
At this pace it would likely take decades just for them to be complete enough to show up on MDN or wpt.fyi
But I agree. With Microsoft ditching their independent Edge and becoming Chromium-based and Opera doing the same we're really down to 3 real engines. The best fourth option we can get are Goanna-based browsers like Pale Moon which are themselves just an early fork of firefox
A completely new and fresh often can go a long way in safeguarding the openness of the web. Even if there's not a powerful company behind it