Not really, and thanks to iOS browser extensions (exclusive to Safari because apple), the few additions other browsers had are now avaliable on Safari.
It’s best to use Safari anyway because close to everyone on iOS uses it. This makes it harder to fingerprint someone, because they all have the same general browser ID.
I’d follow the Privacy Guides safari config. It hardens Safari and adds the best privacy extension to block ads and tracking. It’s the best for iOS private browsing right now.
This isn’t allowing non-webkit browsers, it’s just Mozilla saying they’ll make a sideloaded version if they can. Unfortunately, iOS 17 didn’t add sideloading, and it looks like Apple is programming iPhones to explicitly restrict it to the European Union :(