Apple have the keys that let them control hardware pairing and firmware updates, you can have those same keys in an open ecosystem with open hardware where you can be in control of those keys. You can absolutely have it both ways.
How do you believe that would work? Do you think the average person is capable of operating a robust PKI management system? I want to like the idea but it seems most likely that this would just mean people having the keys on the device which was stolen (because they don't have redundant storage in a separate location), having a compromise mean that someone now has persistent control of all of your devices, and a spike in the kind of social engineering attacks we saw in the desktop space for decades where someone convinces the user to compromise their security because 99.99% of people using computers do not have the experience needed to understand the security decisions they're being asked to make.
