Nor do most PC vendors. Which is why Linux on many laptops is still some kind of a challenge. The only reason it most of the times works nevertheless is, that the PC vendors often use known components and the user base is so large, that a lot of reengineering already had happened. But if Linux on Apple Silicon gains any traction, the situation could be quite good.
While that is important, it's quite superficial given that Apple does not provide documentation for the device.