The whole USB-PD standard is massively over complicated and that makes it a lot harder to implement in home made equipment. You pretty much need a dedicated chip just to negotiate with the power supply. The whole protocol should have been made simple enough to implement on any 8 bit microcontroller and not be locked behind a proprietary standard.
There does need to be some way to negotiate higher voltages. There is just too much voltage drop when you need more than a couple amps at 5 volts.
It would be nice to have a standard for supplying unregulated 48V DC at 1KW or more without any negotiation or electronics required and with a robust connector that won't break if it gets bumped. That would be very useful for off grid solar systems since the power would come directly from the batteries.