That is true, but, there are applications where the majority of the power budget goes to the radio, such as a wireless sensor. I worked with battery powered wifi sensors in the past, and very infrequent transmissions (15 minutes) still accounted for 90+% of the power budget. Average current for a 2-3 second transmission was something like 60-80 mA, with a huge in-rush current on boot. I see this and think it's probably too good to be true in practice for something like that.