You're not thinking this through. For example, you're not accepting that creating a device and then suggesting other people should build it is far less anonymous than buying a mass produced device and recommending other people should buy it. You're pretending there's no point to trying to gain an anonymity set because everything is full of trackers anyway, yet you also pretend you can safely bet the authorities don't know what you print on your 3D printer.

You're not showing me a raspberry pi with a screen that I can buy to use it for web browsing, without it needing further DIY configuration that helps make it traceable