Out of the box it can play audio in the background, and now that extensions are available you can block ads as well. You don’t really need constantly updating 3rd party clients or questionable firewalls anymore if you just want usable youtube on a phone.
I didn’t know Firefox didn’t have extensions on iOS. I would have called it Firefox android instead of mobile. I’m glad there’s still ways for iOS users to do this.
All browsers on iOS were, until very recently, reskins of the Safari engine.