GNU/Linux desktop
often use: Pale Moon, Firefox ESR, and Tor Browser
sometime use: SeaMonkey, EWW (Emacs Web Wowser)

I don't use Chromium. Because, it send a lot of fingerprint to connecting server. (Fingerprint check)
Tor Browser is easy to use for privacy.
Pale Moon and SeaMonkey is forked from Firefox. But, they are lightweighter than Firefox. I use uMatrix addon for privacy and paformance.
EWW is very lightweight. But, many website are designed for Chrome and Firefox. So, EWW can not show those website.

Andoid mobile
often use: Iceraven, and Fennec F-Droid 68.12
sometimes use: Tor Browser, and Bromite

Iceraven is:

• about:config support
• The ability to attempt to install a much longer list of add-ons than Mozilla's Fenix version of Firefox accepts. Currently the browser queries this AMO collection Most of them will not work, because they depend on code that Mozilla is still working on writing in android-components, but you may attempt to install them. If you don't see an add-on you want, you can request it.

I have been using Firefox 68 too. Because, latest Firefox is very heavy.
Bromite setting is anti-fingerprinting.