Yes, you’re right about voltage and amp combined, but the problem is modern phones and their charges don’t generally want to be doing high amps at 5v, they increase their voltage to 9v, 15v or, 20v. Which like you would point out, is not the right voltage.
Personally I just feed 5v in via a ubec like this: https://core-electronics.com.au/ubec-dc-dc-step-down-buck-converter-5v-at-3a-output.html since I usually have some kind of 12v battery powered thing going on with mine and lots of 12v ac-dc adapters for bench testing and charging. Lots of ways to power them but it’s definitely not just ‘grab your usb-c charger and it’ll be right’ which can be frustrating for people since it’s almost all other usb-c things will ‘just work’.
Yes, you’re right about voltage and amp combined, but the problem is modern phones and their charges don’t generally want to be doing high amps at 5v, they increase their voltage to 9v, 15v or, 20v. Which like you would point out, is not the right voltage.
Personally I just feed 5v in via a ubec like this: https://core-electronics.com.au/ubec-dc-dc-step-down-buck-converter-5v-at-3a-output.html since I usually have some kind of 12v battery powered thing going on with mine and lots of 12v ac-dc adapters for bench testing and charging. Lots of ways to power them but it’s definitely not just ‘grab your usb-c charger and it’ll be right’ which can be frustrating for people since it’s almost all other usb-c things will ‘just work’.