Average person? Probably not many. But it’s also not some expensive, rare, hard to have thing. I have several raspberry pi’s that could easily serve the purpose by just not connecting a new image to a network.
Yeah the cheapest way, too bad the rpi 4/5 and future versions make it possible to write to the eeprom. Atleast it sounds like the newer ones have a way to make it write protected via a jumper or something.