This is outdated, I guess we gonna fix this info soon. The real system requirements are here: https://www.firefox.com/en-US/firefox/ios/145.0/system-requirements/

It is current on https://support.mozilla.org/en-US/kb/firefox-available-iphone-or-ipad-my-language as it says ''Firefox for iOS is available for iPad, iPhone and iPod touch devices that are compatible with '''iOS 15.0''' and above''. Firefox for iOS/iPadOS has required 13.0 as of Firefox 99.0 then changed to 14.0 as of Fx 112.0 then changed to 15.0 starting at Fx 120.0 https://www.firefox.com/firefox/ios/120.0/system-requirements/ In https://support.mozilla.org/en-US/kb/will-firefox-work-my-mobile-device/history it looks like the outdated iOS 8.2 was done way back on Dec 31, 2015 as it was the Android version that was kept more up to date in article. Based on some searching it looks like when Firefox was first available for iOS/iPadOS back in 2015 the minimum around that time was iOS 8.2 then later went to iOS 10.3 not long after.