On paper the USB-C port is able to deliver more wattage than the older types, but nowadays, most every manufacturer have their own proprietary "fast charger" protocol, and if the charger does not respond then the device will assume that the charger is a "slow charger" and only draw a fraction of what the port is actually able to deliver.
This is actually a good thing, we dont want someone to buy a cheap USB cable on alibaba, with not a lot of copper in it, and then the device tries to suck 60 Watts, making the cable light up like a lightbulb.
Oneplus for example, have their own proprietary protocol called warp charging, the charger will have to be able to do a handshake to prove it is able to do the wattage then phone or tablet wants, and it also needs a cable with a chip inside, that essentially says "Yeah, i am a capable cable, bring it on".
Qualcomm has their own protocol, apple has theirs, Samsung has a different one and so on.
Some of the "cheaper" brands use the Qualcomm one so any QC2/3 charger will be a fast charger for those phones.
It would be nice if every brand and make would use the same protocol, like EV's do now, where a CCS charger can charge any CCS capable car, and both the charger and the car, can say "I can handle this and that much" and they just charge at the fastest speed both car and charger can agree on.
