I'd really love to switch back to Firefox from Chrome but it's just so sluggish on my Android phone and I had the same issue with an iPhone a few years back. Why is this, really?
For me it's the opposite: Chrome on Android is not usable because of all these ads.
If you do not want to use Nightly, then the normal Firefox together with the addons "ublock origin" and/or Privacy badger should not be much different than Firefox Focus, but still allow for tabs.
https://addons.mozilla.org/EN-US/android/addon/ublock-origin...
https://addons.mozilla.org/de/android/addon/privacy-badger17...