Wait, so you live in a country where there is no government that can provide an ID? How does it work when you travel abroad? Do you have multiple legal identities, with different names and nationalities, that cannot be individually tracked back to one government?
> you specifically talked about an OS without user changeable software, thats the definition of open source
No? Open source is about your ability to reuse the code. You can modify and install Android (or let's say AOSP) on most Android devices (look at the list of devices supported by LineageOS for instance).
The one thing you cannot do is modify it and get your changes signed by Google.
Remote attestation is about preventing you from leveraging open source software, but the software is still open source.