A 7.5W charger is 50% more powerful than a 5W charger and yet, only provides 21% more power according to the graph. If we use those differences, then a 12W wireless would produce only 76% of a charge in 60 minutes, compared to 72% by a wired charger. As you can see, there's greater loss from wireless and that loss increases as power goes up and heat loss increases.
Additionally, wireless charging creates far more heat than traditional wired charging. Heat is the biggest enemy of battery health and leads to lower overall capacity and faster drain times. So using wireless charging negatively impacts your battery life with time and causes you to need to charge more, which then leads to even less battery life in a cycle until you need to replace the battery.
Wired charging doesn't suffer these same losses wireless does as wattage increases.
