First of all, 8 pins are used for power delivery for just VBUS & GND. Furthermore, you need the two CC pins or otherwise you won't get any voltage from USB-C c

First of all, 8 pins are used for power delivery for just VBUS & GND. Furthermore, you need the two CC pins or otherwise you won't get any voltage from USB-C chargers. USB 2.0 data pins are needed for backward compatible charging (otherwise a compliant device could only pull 500mA from a USB-A to C cable). The spec defines such a receptacle connector for USB 2.0-only support (also including the two sideband channels, but that's only 2 out of 16 pins, so probably not noticeably more expensive).