I like uMatrix (from the creator of uBlock Origin), which by default blocks almost everything from 3rd parties, especially javascript. Without javascript, privacy concerns are vastly diminished and the pages is much smaller and faster. I like uMatrix because it's relatively easy to load only the javascript you want, when you need it.
In theory i'd rather use Firefox over Safari. However in practise, a lot of stuff doesn't work properly in Firefox - because of some extension or some about:config setting i set after reading posts like this.
When that happens, i always revert to the trustworthy Safari which just always works (...and has proper pinch-to-zoom, which in my opinion is a very basic feature Firefox is lacking.)
How odd, my experience is completely different.
I browse all the time in Firefox and Chrome with uBlock Origin and Pi-Hole. Not much is broken. In the rare case something is broken I flip DNSCrypt on and use Safari/Edge which don't have uBlock Origin installed. That happens like, what, once a year?
It would be nice if Firefox had a page that listed every setting that is changed from a default value in one place. You'd still have to investigate extensions separately, but at least all those obscure hidden settings you've changed accessible and visible in one place.
On about:config, sort after the "Status" column. That'll give you a list of all modified values.
And more importantly, when I need to bypass these safeties by using another browser, I'm doing so intentionally: I know this site is trying to move outside my security comforts, and can address it accordingly, rather than any given website abusing my privacy.
And of course, if I switch browsers just for sites that don't work in my Firefox setup, they're loading in a browser I use for little else... so they don't find much anyways.