>the dashboard could be just a double DIN slot and a heavy-duty, universal tablet mount with a 100W USB-C PD port. The car provides the power and the speakers and my phone provides the maps and music.

Legally mandated backup cameras make your idea DOA.

In fact, nearly everything terrible about cars in the last decade can be traced to regulations in some way.

Wondering why transmissions are insanely complicated and unreliable now? Manufacturers were forced to eek out an extra couple MPG due to continually tightening environmental regulations. Something has to give.