That may be true on desktop. But, unfortunately, the mobile app is way behind chromium. From being unresponsive, to outright buggy. It’s not a good experince. It’s been 2 years since the rewrite but it’s not getting much better or even close to fixing most of its issue. Meaning, using firefox on android is a handicap on yourself.
I have used Firefox on many smartphones since 2014. It’s not an anecdotal experience of mine. It’s the difference between chromium based browsers on android being more efficient compared to Firefox. Here’s the github issue which was open from 2020, now moved to Bugzilla: https://github.com/mozilla-mobile/fenix/issues/12731#event-8105829420
If this did not happen it would not have been kept open for so long. Just search tab reload in closed issues you will people still complaining while the repo was accessible.
Bugzilla issue from 2 years ago: https://bugzilla.mozilla.org/show_bug.cgi?id=1752594
The migrated issue from github: https://bugzilla.mozilla.org/show_bug.cgi?id=1807364