Apple M1 isn't in a proprietary walled garden, it's a general purpose computer like any good old x86 laptop. It's not designed with industry standards in mind and doesn't have any official documentation on internals, but it's not locked down in any way, and reverse engineering is solving the documentation problem already.
(Also Qualcomm Snapdragon is a far more cursed platform internally.)
(Also Qualcomm Snapdragon is a far more cursed platform internally.)