It's not magic when step down DC-DC converters take as much space as power negotiation crap and all that's really needed is single 20 volts. Look at new ATX standardization development with proposals to leave only 12 volts, dropping 5 and 3.3 - that's the right way to standardize on power delivery. What USB-C is doing is not standardization, but an attempt to undermine standardization to profit from selling expensive cables and locking people into brands, just as device manufacturers did with non standard ports for mobile phones in the past and were eventually fined for it and forced to use standardized USB power delivery.

Not all USB-C cables support PD!

And not all PD-capable cables support every range or combination of voltages and wattages.