Hmmm didn’t think about that, but this would be either unfair competition, as Apple has addons for Safari, or when Browsers can be downloaded from their websites directly an inevitable consequence of EU (and later other states) forcing the app store to be competitive.
Apple is going to allow alternative browser engines, like Gecko which desktop and android Firefoxes are using. Firefox on iOS is nothing more than lesser version of Safari/webkit with Firefox interface and lacks proper blocking and other features. It is expected that Apple allows alternative browser engines when iOS 17 launches.
At that point I hope we can get proper Firefox addons for it! Like uBlock Origin.
Or even better, care about your digital privacy and ditch Google and Youtube and use an alternative front end, like invidious, or piped.