The argument would be that they didn’t want iPhone users, especially with early models, to end up choosing other engines that were much worse on battery life and that would hurt the image of the iPhone. Back then, there was no battery settings where you could see what was eating your battery. It was all opaque and could make people think the device had lousy battery life.
And yeah, I think it’s unlikely someone could have made a more efficient browser than Apple since they didn’t give public access to all of their functionalities. And that might have been partly for security reasons, if there were less-secure aspects to hidden functions, for example.
The counter-argument is that they should have opened everything up, but Apple will say they were going as fast as they could responsibly go, and that’s why there were limitations that have been relaxed over time.
That feels like an argument that could apply to bar any category of apps to compete with Apple ones on the phone.
For instance giving a special placement to Apple Music and not allowing other apps to get the same privileges, because music playback needs to be efficient, and a bad music experience would hurt the iPhone's image. Same for movies, same for ebooks, same for spreadsheets (including needing to execute macros, so security risk is through the roof)
I feel I could get paid by Apple to come up with excuses for each app they need any.
The real justification for browser engine restrictions is not battery life but security.
If you look at any iOS vulnerability reporting, Safari is a big weakness and often the source of zero day attacks. Browsers are hugely complex pieces of software with a lot of attack surface. A large part of Apple’s value proposition is being secure. It sounds like the new approach (in the EU only) that allows additional browser engines requires specific security measures to be taken.
Rightly or wrongly device security is going to be a strong defense Apple has against some of these allegations.
Then by the same argument, it should be ok for Microsoft to prevent users from installing any other browser on Windows besides Edge because it could make that person’s device less secure…
No, a user should be allowed to take the security risk of installing whatever they want on their computers. Security-conscious users will have clean phones, and ordinary users will have phones full of viruses like their computers.
Are we ruling out the possibility that competitive browsers could offer better battery performance, too?