I switched to Firefox some years ago but still dabbled with Chrome, up until FF introduced multi-account containers that is. Performance results always seem to be subjective, but in my opinion Quantum made FF an absolute beast, even when running the usual lot of security add-ons like NoScript, uBlock Origin, Privacy Badger, etc. However, Firefox Containers I would argue is the number one feature from a usability stan…
FF Focus is based on Chromium.
Notably though, Focus is on track to move away from it's Chromium roots:
"The switch from Chrome WebView to Gecko doesn’t seem to be performance related. Instead, the reason has to do with the core goal of FireFox Focus in the first place: privacy. Mozilla has found a reason to believe that the Chrome WebView engine can leak someone’s data. So in the spirit of maintaining data privacy, the team behind Firefox Focus has decided to switch to the Gecko engine." [0,1]
[0] https://www.xda-developers.com/firefox-focus-switching-chrom...
[1] https://github.com/mozilla-mobile/focus-android/wiki/Release...