While there are no technical reasons it couldn’t be done, the performance in this specific case would be abysmal. As an otherwise happy PinePhone owner the performance is sadly lacking even in native applications.

Maybe the PinePhone Pro could handle running it somewhat smoothly.

I feel like Apple would become very irritated if someone ported iOS to the Pinephone (perhaps using a thin hypervisor layer).

That would be a funny departure from the typical Emulator + ROMs use-case that is retro gaming.