Charging through the USB-C port has had a tangible impact on the amount of chargers I carry when going outside. The last time that I traveled, I took a single charger with me, even though I had three devices. (All of them supported the USB-C Power Delivery (PD) protocol. The charger was also a USB-C Power Delivery - Standard Power Range capable device.) The devices were able to negotiate whatever power they wanted with the charger. This is a great improvement to having multiple cables for multiple devices. This is not the full picture though and has probably lead to more confusion for many people.
Not all devices that have a physical USB-C port support the USB-C PD protocol. I am repeating what many articles online have already explained. I ran into this firsthand a few days ago, when I attempted to charge a device that was completely discharged. I tried charging it with multiple power sources: a wall socket adapter, a laptop’s USB-C port, a laptop charger with a maximum voltage of 100W. In all these cases, despite being plugged in for many hours, the device did not show any sign of being alive. I guessed that the battery was dead and I would have to dispose the device.
A day before throwing it out though, something bugged me about the USB-C port on the device, and I decided to try to charge it with a non-USB-C PD enabled charger: a simple wall socket USB-A adapter and a USB-A to USB-C cable. Voila! The device turned back on after about 15 minutes!
The chargers I used do not seem to have supplied the minimum power that that was required to turn the device back on, or perhaps as this device does not have USB-C PD support, they probably just gave up and did not supply any power at all. This is not how the specification is worded, with this technical note saying that chargers must deliver the pre-Power Delivery protocol power on the USB-C connection upon initial connection. The gulf between USB specifications and their implementation has once again come back to bite us.