Unfortunately, the issue with iOS browser ecosystem is due to the proprietary lock-in by Apple. Third-party browsers on iOS, unlike android are just a skin on the top of Safari i.e. they are forced to use the WebView API instead of a full-fledged browser engine.
So, Chrome/Firefox on iOS are not even close to what's available on android/desktop; thereby unable to use all functionalities incl. extensions in the case of Firefox. In-fact, not even Safari extensions can work with Firefox on iOS due to Apple's proprietary lock - https://support.mozilla.org/en-US/kb/add-ons-firefox-ios.
This makes iOS device dangerous to even browse the web, once the OS updates stop as safari doesn't get update via Appstore, leading to exploitation of vulnerabilities - https://googleprojectzero.blogspot.com/2019/08/a-very-deep-dive-into-ios-exploit.html. Where as a 7 year old android device, can still receive latest Firefox from Playstore although OS updates are not as good as iOS ecosystem in android.