Just want to chip in on the mobile browsers. A big issue is that webview is chromium based. So even if you use Firefox on android , you are using chromium/chrome plus Firefox.
Options on mobile would be vanadium (only on graphene I believe) or bromite (on F-droid). Bromite has its own webview separate as well , crashed my phone many years ago , no idea about it now.
On PC (Linux) I use Firefox with chromium as backup.
Also fuck brave ,why support shady bigots if you can avoid it?
Firefox on Android uses GeckoView, which is a reusable Android library that wraps Mozilla’s Gecko browser engine. GeckoView is similar to WebView in some ways, but it has its own APIs and is not a drop-in replacement. GeckoView is full-featured, self-contained, and standards compliant.