The M1 can run Linux after an extensive reverse-engineering effort. And Apple didn't take particular active measures to prevent running your own OS on it; they

The M1 can run Linux after an extensive reverse-engineering effort. And Apple didn't take particular active measures to prevent running your own OS on it; they just didn't offer any help. Many Android device manufacturers actively try to prevent that. Apple actively tries to prevent it on iOS devices. Some early Chromebooks actively tried to prevent it, too. (Though not Google's own flagship developer devices.)