It may be hard to believe, since its wireless charging power is only 7.5W, but I can see why people believe an iPhone wirelessly charges faster than other higher-power charging phones.

There was a time in the early years of wireless charging when Qi* was only a 5W standard, officially referred to as the baseline power profile (BPP).  All phone chargers...

There is only one thing that a phone manufacturer can do to maximize the wireless charging rate of a Qi compatible phone.  They need to minimize the heating of both...

The takeaway from my research is that one should ignore wireless charging power numbers listed on a box or in marketing literature.  In my opinion, it means essentially nothing.