I came back using Brave for the most peculiar reason: I thought "With all the browsers I've installed, why not dedicate one to Facebook, one tab for the main page, one for the messenger?"
I discarded my main browsers, and the ones I already use for dedicated purposes (namely Opera and its VPN), so the remaining choice would be between Brave, Vivaldi and Pale Moon/Arctic Fox/Basilisk.
Vivaldi has an historical issue with some video format and Pale Moon/Arctic Fox/Basilisk didn't gave satisfactory results for one reason or another.
Instead, the current version of Brave is acting quite like Water/Fire-Fox or Chromium and accepts nowadays apparently all of Chrome's extensions!
So I could customize it just to my taste with Chromium Wheel Smooth Scroller, 1Password, F.B.Purity, Stylus (with "Clear dark facebook by book777", my favourite Dark mode) and Deluminate (for other sites than FB).
Except for one crash today, it's working just as expected.