> On an (X86) PC you can tranfer your disk, as it is, to a new X86 architecture and it will run.

This is because of a supporting set of standards (BIOS/UEFI/ACPI) that are well-supported on x86 systems, but technically independent of the x86 ISA. BIOS, and the general compatibility you're talking about, is a historical artefact of the IBM PC being so dominant in the market that other companies created compatible computers. UEFI and ACPI actually exist in the ARM ecosystem now. If ARM continues to grow outside of mobile devices, you could eventually see the kind of broad compatibility you're talking about. It's not super likely though. All signs point to the consumer computing ecosystem becoming more closed, rather than more open.