Yes, but Firefox focus is Safari. Chrome is safari.
iPhones aren't allowed to have web browsers that aren't running Safari on the back end. They can have different names, different UIs, but at the end of the day it's the same browser.
And JS engine, the whole thing is basically safari with a different URL bar and ancillary stuff like bookmark syncing. As far as the code is concerned it's 100% Safari.
I don't know why non iOS browser play the stupid pseudo support game with Apple, it just makes it confusing for users like the parent comment... playing into Apple's hand, helping them pretend that it's actually a fair ecosystem with choices.
> I don't know why non iOS browser play the stupid pseudo support game with Apple, it just makes it confusing for users like the parent comment...
That's easy. Users want their bookmarks, history, passwords, etc synced across devices, and so if there's no Chrome, Firefox, Edge etc for iOS to accomplish that on iPhone/iPad, people who have multiple Apple devices would likely switch to Safari and those users would be lost. Additionally, in the case of Google and Microsoft, they'd be opting out of those sweet, sweet streams of user data if they had no iOS presence. And so, those browsers exist, just built around WebKit instead of Blink/Gecko.
iPhones aren't allowed to have web browsers that aren't running Safari on the back end. They can have different names, different UIs, but at the end of the day it's the same browser.