Not exactly.In your first statement, you are saying that you would have to buy a new wall wart for the pricy item
1) I would choose to buy a new one, not "have to".
2) New devices are often larger in batt capacity, so it could be the case that the old wart is just a 27w PD but new device really needs 60w or 100w wart to charge "fast", hence you have to buy new.
Are all warts that have C port the PD types?If you connect two USB-C PD supplied together with a USB-C to USB-C cable, prepared to ne bored and underwhelmed. What happens? NOTHING. Both identify as a supply and neither as a consumer, so neither supplies power.
It's almost like the designers considered the possible problems.





