DeLLiAnOdis is pretty accurate.
Better to charge slower and less heat then other way around.
By the way, in your picture with the text of charging time van 0 to 100 in just 42 minutes * You must always look at the page below what the extra " * " means behind a word or specification. Always look for a * if they promise a specific thing
And dont forget, companys that promise you more miles/km with one tank of fuel, faster battery charging, better cold with less energy in refrigirators and so on and on.... They achieve this by creating perfect conditions, or by turning settings or stuff out.
Danishbluntespecicaly when asus reduce the speed like xiaomi but they reduce to every one and not depend on the heat of the device
dis is pretty accurate.
You don't need to buy a wattmeter, because it's common knowledge that phones don't charge at their potential max speed.