> What you need is the ability for consumers to replace the firmware.

I don't think that's enough. Most people aren't going to replace the firmware on their device with an open source replacement made by someone else. Now if the firmware was required to be open source, and automatic updates could be seamlessly switched over to a non-profit or government agency in the event of the company going out of business, you might have something. But there would be a lot of details to work out.