Mobile gaming is about 10x the size of the PC and console markets.
AFAIK developing countries are dominating mobile gaming for a simple reason that they cannot afford PS/Xbone/PC. Ergo no iPhone for them to begin with.
It might be because they code very inefficiently, and they might also be doing a ton of crypto and anti-hacking calculations in background, but these games are surprisingly taxing for the phone they're running on.