You'd either need to be able to restart the device with the existing buttons in a way that could not lock up or perhaps configure a physical rather than software power control...or so I guess. These are not insurmountable problems. MacBooks have been like this for years.
But if a MacBook gets into a frozen situation you can intervene during the boot sequence, that’s not the case with iOS devices. Even in DFU mode you need to have a physical connection. Of course anything is possible if Apple changes everything to have a device without any port.