Given that Apple silicon is pretty new my guess it porting and testing , I would also add not all ARM chips are exactly the same , there will be some minor nuances for sure .
Perhaps it is also some funding and access to the kits and dev time , updating gcc is not a full time job for most of the contributors after all.
This is a great thread, thanks! (And I see that your name is in the thread.)
I gather from there that previous efforts to target iOS are outdated, there is substantial work to handle the Apple ABI, and that it's not been seriously looked at yet.
