Jeff Atwood wrote about The state of Javascript on Android in 2015.

It seems the Android manufacturers are more interested in slapping n slow CPU cores on a die than they are in producing very fast CPU cores. And this is quite punishing when it comes to JavaScript.

This is becoming more and more of a systemic problem in the Android ecosystem, one that will not go away in the next few years, and it may affect the future of Discourse, since we bet heavily on near-desktop JavaScript performance on mobile devices. That is clearly happening on iOS but it is quite disastrously the opposite on Android.

The iPhone 5S from two generations ago outperforms the latest Samsung Galaxy devices.