But thats not point here. Everyone is talking about the climate change and then we want to charge millions or billions of phones with ~50% extra power?
In absolute terms it's nothing though. An average household uses 4000 kWh of electricity in the UK (less than half of the average us household), so saving the 5kWh on 4 phones is a 0.5% saving, which is roughly equivalent to running your home boiler for 10 minutes per year. Turning off your thermostat for one evening would have the equivalent impact of not using a wireless charger for a century.
Do we not have enough symbols? Plastic bags, domestic recycling, plastic straws are all strong "symbols" and yet we're still fighting about a couple of kWh rather than making any meaningful change.