Yes, you can change the fonts in Vivo X21.
Yes, Vivo X21 does have the eye protection mode.
No. Vivo X21 has MicroUSB. It does not have the USB Type-C port.
Yes, Vivo X21 does have the fast charging support.
Vivo X21 is an all-rounder with good performance, decent camera performance and a snazzy new in-display fingerprint scanning technology at the heart of the device.
For the most part, the X21 is a worthy mid-tier device.