On our apps we consistently see a p50 3-4x speed difference between iOS and Android (though there are more lower end android devices). Hard to fathom if it's all due to variability in android devices vs RN being less performant on Android.

Pixel 9 Pro, or virtually all android phones apart from the recent snapdragon Elite and coming ARM Cortex X5 all have much slower single threaded performance comparing to iPhone.

The Google Tensor G4 in single thread and integer only is roughly in between iPhone 11 and iPhone 12. That is the performance between 2019 and 2020 on iPhone.

And Tensor G4 is already on the high end Android Phones. You can quickly see how all previous and lower end android phone are much slower.