But a C64 already fits that criteria and costs a lot less than $500. The FPGA that runs the video, the SD card controller, and probably a few other things are more powerful than the entire rest of the device and certainly not understandable the way a C64 was. The philosophy behind it feels incoherent. He talks about some future version being as little as $50, but my understanding from other videos is that that version will lack features and probably all be running on FPGA or something anyway.

Why not just emulate the entire thing on an FPGA from the start and pretend it is simple? Or skip the FPGA and use whatever computer the user already has?

Suffice it to say I just don't get it except as some kind of artistic expression, where even then I think it fails to have coherent vision.