Various websites suck in one browser or the other or simply don't work in more than one single browser. We're not that far away from the days when Internet Explorer (IE) was the only thing that loaded a site (often for something work-related... groan)
That said, if you need Chrom(e/ium) and want a non-data-sucking version, I think Ungoogled Chromium is your best bet currently.
For the Firefox side of things, there are already several forks that aim to do things differently/better. Floorp is one I see recommended regularly. There seem to be a larger number of Firefox forks focusing on security/privacy than Google forks, but this is the most well-regarded from my research.
Simultaneous post-enshittification from both Chrome/Chromium and Firefox is probably (hopefully) leading towards more active development/contribution to these (and other) forks!
The last three sentences are not quite accurate. It's not necessarily that nothing existed before the the big bang. It's a singularity event where mathematically we can simply not know what existed at/beforehand that moment. It is somewhat comparable with the event horizon of a black hole.
There is something happening/existing, otherwise a black hole would not be able to occupy space or affect light. We simply do not have the ability currently to understand what that is.
By definition, that is not nothing. It is a that we cannot know/understand it, at that moment. Notably, a lack of evidence is not evidence of nothing.