If JIT is such a problem then Apple shouldn't use it themselves. Sure, they let you disable it but it's still enabled by default while everyone pushes the narrative that Apple is all about security.
JIT isn’t the problem. It’s giving control of JIT to third parties.
We can still hate on Apple, it’s just more accurate to say they don’t trust their own app sandboxes to stand up to LLVM / assembly attacks from malicious apps with JIT access.
I just don't buy that it's a special security concern at all. There are so many other possible security vulnerabilities to exploit that don't involve a JIT compiler. So why would Apple specifically restrict third party apps from JIT?
It's realistically just another way to ensure they maintain control over app distribution. Safari sucks for web apps. Third party browsers are just different shells over Safari on iOS. Apps built on things like React Native support hotfixing without slow app store reviews - but your app will be slow without JIT and rules force you to still go through reviews for feature changes.
