> I hope that continued advancements in AI make it impossible for outfits like Apple to maintain closed systems that lock the device owner out of having any control over their own hardware.

Formally verified bootloaders and Secure Boot will make this all but impossible without hardware mods that do voltage glitching. It took 8 years for the checkm8 and usbliter8 exploits to be found, and I think that especially Apple has invested so much money, time and resources into securing their boot chain that the "best" thing we can hope for is a tethered jailbreak allowing a boot into another kernel.