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.
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.
If your eyes hurt then switch to literally any other apple device, Apple TV, Mac, iPad, iPhone… they all have access to Apple Arcade. When cloud gaming streams asset objects and not raw video, then it’d be a contender. As of now, it’s too expensive and is losing to mobile games
But, if you are referring specifically to the new GPU with accelerated raytracing, I want to add something more.. Remember that for many years now, every innovation that Apple has produced has been secretly developing towards AR!
For this reason it makes perfect sense.. Raytracing is SUPER important for the kind of rendering needed to make AR/VR look realistic