It’s funny that companies like Google have stopped giving chargers in the name of being ‘environment friendly’ but in spite of conforming to USB PD standards, third party chargers can’t still charge the Pixel Pro to it’s maximum capacity, so you are essentially forced to buy one.
The summary is wrong. The article says 3rd party chargers can’t charge the Pixel as fast as Google’s proprietary charger. (45 Watts for Google vs 37 Watts for everyone else.)
Any charger will charge it to maximum capacity.