Wired (and others) report that 20W number because I think they’re misinterpreting the Apple fast charging documentation, which explains that fast charging is available with a 20W charger or above. They’ve explained this for all the previous USB-PD compliant models, but real world testing has shown actual charging rates of up to 30W for the iPhone 14 Pro. I imagine the 15 and the 15 Pro will show similar numbers at the high 20’s, maybe even 30 watts.