A privacy fork can only do so much if Google keeps removing underlying things that make it possible. The more it diverges from upstream, the harder it is to maintain.
Under that specific scenario, we would get the best of both worlds. There would be less engine variety, but it would save Firefox and offer an out of a Google owned ecosystem.
Now I think that's absolutely not trivial, and if Firefox could pull that out it could probably as well push its own engine way more forward right now.
For instance Apple played that game, ended up basically alone on Webkit, and I'm not sure Safari is more competitive to Chrome than Firefox is. Safari keeps some market share, but the reasons are elsewhere.
It was neither, it was a legal issue. As I understand it, EU law (or its most common interpretation) did not actually allow websites to just defer to a browser preference. Fortunately, the EU is about to fix this:
> The amendments will reduce the number of times cookie banners pop up and allow users to [...] save their cookie preferences [...] in browsers and operating system. (https://ec.europa.eu/commission/presscorner/detail/en/ip_25_...)
As I understand it that's exactly why Apple took webkit and ran with it.
> Cookie Banners?
People really viscerally hate those, do they. That anger should be pointed to the site pushing them IMHO, but aside from that, dismissing the banner is in itself a legal choice (whatever the default was) that isn't only bound to cookies despite the name. Whatever happens on the backend or service can also be bound to that choice.
I look at it the same way we have newsletter checkboxes. They're a PITA but I wouldn't trust an automated system to make the right choice on every single form, and not sign me to some super weird stuff just because it thought the checkbox was a newsletter optout (imagine a site pushing a "bill me every month for the extra feature" clearly explained option, but with an html input id close to "opt_out_of_free_plan" and it's automatically checked by your browser)
don't forget the decade of -my-shitty-browser-extension: somethingdumb;
> Do you think Chrome gives a shit about the Internet? No.
If they fork it sufficiently to not be tied to Google's decisions, they're once again maintaining their own engine (see also: WebKit vs. Blink).
If they don't, they'll be at the mercy of whatever Google decides (see also: Manifest V3 in Chrome).
Chromium is so prevalent as an engine, that most developers don't test their code on Firefox and just tell everyone to use Chrome/Chromium when they run into issues.
This has the unintentional side-effect of strong-arming the W3C into compliance with the engine and not the other way around. Why do we bother with the W3C then? if they are powerless and Chromium can do as they please?
What I mean is, it's basically a VM. It's got a screen, inputs, storage, networking.