>The solution, I think, would be a regulation that forbids manufacturers of any chip or device CPU from making obstacles to reprogramming the device (using fuses, digital signatures, encryption etc).
Why would you make essential security features illegal? Do you want to fly on a plane where the flight control software was maybe overwritten?
>So if you buy a device with CPU and writable memory, you should be able to load your own program and manufacturer may not use technical measures to stop you.
The problem is Google and Apple locking down their Operating System, this is not a technical limitation on hardware.
> Do you want to fly on a plane where the flight control software was maybe overwritten?
I don't understand it. Whoever owns the place can replace any part of it, including computers. So being able to overwrite software doesn't change it. Furthermore, plane computers are not a consumer hardware.
You could make a better example with patched car software.
> The problem is Google and Apple locking down their Operating System, this is not a technical limitation on hardware.
The initial ROM bootloader contains hard-coded signature which prevents you from replacing Apple/Google software.
On pixel devices you can add your own signature to be checked and thus can use secure boot with a custom OS - that's how GrapheneOS works.
No need to strip out every wall, we just have to think about the problem and put doors at necessary places so we can enjoy both freedom AND security.
Security only works if you can control what software is trustworthy. If some software has been proven to be untrustworthy, it is worthwhile to prevent all software that the producer has ever made from working at scale. Adding some nominal process and fee to make it too expensive to create a lot of accounts prevents them from creating hundreds of alternative aliases. There is a lot of precedence for why this is a good idea and works. I think if there was another company involved with performing the audit which folks trusted it might now seem so scary.
Do you understand that you are advocating for a world in which two corporations are the sole determinator of the livelihood of all mobile software developers? A career in software development should not be at the complete mercy of Apple and Google, or I suppose if you had your way Microsoft for PC gatekeeping as well.