> Apple has a JIT restriction because JIT introduces native code that was not present during app review, and app review is where they prohibit calling non-public APIs, at least historically.

Another regrettable thing about our industry is the proliferation of locked-gate-in-an-open-field-tier security theater. Apple's PROT_EXEC restriction has zero security benefit: anything JIT-compiled code can do, interpreted code can do too.

(In the same vein, macOS Santa (used by many a tech company to police programs runnable on Apple developer endpoints) doesn't restrict script launches at all. The interpreters that Apple ships with macOS have built-in FFIs like Python ctypes that enables programs launched using these interpreters to do anything a Mach-O binary can do.)

While I respect the sweat and cleverness that went into making JS runtimes work efficiently while wearing Apple's no-PROT_EXEC hairshirt, none of this work ought to have been necessary. Imagine how much further ahead the industry would be if these big brains had focused on solving some other problem.

I totally agree that the lack of JIT has been a huge waste of human resources. NativeScript and React Native have had to move so many mountains to make viable software despite it.