Qualcomm is that starting with QC4.0 the company has switched over from their own proprietary charge negotiation protocol (Essentially what Quick Charge originally was), to the USB-PD (Power delivery) standard, with the product branding being more of a overall certification platform as well as charge solution on the part of the phone’s internal charge architecture.

Today’s newest Quick Charge 5 in that sense is an evolution of what’s offered by the USB-PD PPS standard (To note: QC4 was already compliant with PD-PPS, although not actively using it as the voltage adjustment protocol), fully taking advantage of the voltage ranges of the spec to supply power to up to 100W.

This guys still add little spice of their own patented things, as otherwise it is hard to get more money via special "certification".