What they don't mention, is that WiFi on iPhone is horribly broken, and it seems that every Wifi vendor has to workaround the issues (everyone from Ruckus to Unifi has to specifically target the iPhones). The only thing more broken is the Fitbit Aria.. In fact, on OSX, we discovered when a computer was in sleep mode, it kept hanging onto its DHCP address until the lease expired, even if the entire network was reset whilst it was turned off.. So junk like that saves battery life, but its bad behavior.
Also, changing the DTIM on a wifi AP can have a significant impact on battery life too.
It wouldn't surprise me if iPhone consumed more battery life, simply because there is less competition and a smaller market, so there is far less incentive for hardware developers to optimise their drivers for that platform (not even sure if Apple or hardware developers code the drivers though).
The only reason people think of Apple's software and hardware as stable and the worlds best, is because of clever marketing, and sheep.