Apple has pulled off several big hardware transitions: 68k -> PPC -> x86/x64 -> ARM. One reason those transitions are considered successful is that they did a masterful job of managing expectations. Apple showed that the consumer hardware market really doesn't care enough about backward compatibility to affect the bottom line. And thanks to Moore's law, supposing you can legally acquire a ROM, your M1 Mac will happily run 68k and PPC code in addition to the officially supported x86/x64 emulation.