Note all the extra electronics on the PD-Buddy-Sink, which OP specifically calls out: "Chips like the popular FUSB302 which only provide the wire level handling of the USB-PD protocol, require a lot of software work to make them reliably operational. And that software will need to run on a µC which adds to BOM." You can see the large STM32F(!? way overkill) on the PD-Buddy.
The STUSB4500 OP used allows for a much smaller, fully-integrated solution.
Note all the extra electronics on the PD-Buddy-Sink, which OP specifically calls out: "Chips like the popular FUSB302 which only provide the wire level handling of the USB-PD protocol, require a lot of software work to make them reliably operational. And that software will need to run on a µC which adds to BOM." You can see the large STM32F(!? way overkill) on the PD-Buddy.
The STUSB4500 OP used allows for a much smaller, fully-integrated solution.