ARM isn’t plug-and-play like x86 (n.b. it could be, but no one does it outside of servers)

You have to write a big JSON like file, called a DeviceTree, that describes exactly what is in the computer

Unless Apple decides to support Hackintoshes, their OS won’t have devicetrees for other devices.

You might be able to make your own and get the OS to read it, but it still has to be for a specific machine rather than generic like before

postmarketos has builds for the 4/5, and Fairphone has already submitted devicetree files for the 6 to the mainline Linux kernel: https://lore.kernel.org/linux-pm/[email protected]/