Infuriating. Closed documentation for essential hardware is a huge hidden problem with today's tech scene in a way that I doubt anybody but the most interested nerds understand.
Things like datasheets for smartphone chips, network devices, components like the superIO chips mentioned here, they are so frequently hidden to anyone without at least hundreds of thousands to maybe millions of dollars to throw at the manufacturer.
Why's it so hard to run anything but Android on the galaxy s1000000? Because it's nigh impossible to write all the drivers for it with literally zero access to any of the documentation for the hardware.
There are so, so many devs out there that would modify the software or firmware on their devices to make the world a better place (extend the life of IoT devices whose subscription services have vanished. Add features and fix bugs in all those random tiny things around your house. Repair devices whose storage has somehow been corrupted. ) but because a few rich dudes go "hmm I'm not SURE about it but it could maybe reduce our profits somehow eventually", we're stuck in this world of garbage