Why are there so many fast charging standards, and what's the difference between them?

Fast-charging now uses many proprietary protocols such as Qualcomm Quick Charge, Oppo SuperVOOC, and Xiaomi HyperCharge, while USB Power Delivery with PPS is the closest universal standard, supporting up to 240 W in version 3.1. Flagship phones—including the iPhone 17, Samsung Galaxy S26 Ultra, and Google Pixel 11 Pro—rely on USB-PD/PPS for 45-60 W charging, but reaching peak rates requires a compatible charger and cable; a USB-C port alone does not ensure fast-charging capability.