Android has like 90%? worldwide market share and most phones are way underpowered vs even old iPhones. Picking a solution that only works well for SV users is a terrible decision.
I recently came across a ridiculous example of a high-end Chinese phone (700$) where one our web app's interactions that normally is near-instant, took 6s instead. Turns out that besides the generic issue of poor JS performance on Android (due to CPU), this particular manufacturer decided to deliver on their ridiculous battery life claims by...running all JS on a low energy CPU core.
Well yeah would you expect it to be otherwise? These devices cost a fraction of an iPhone.
People in the US don't realize iPhones are luxury products for the majority of people in the world.
"by...running all JS on a low energy CPU core"
Android including Chinese Android at best are ~75% market share.
But your point still stands though.
But yeah my point is that US devs (specially SV devs) tend to be myopic about this as they are using iPhones like most people in their bubble. If you're making an app for the US market then this is probably less of an issue, but for worldwide audience this is a huge issue. Not only with RN but with web apps too.