You can also integrate other native widgets not designed first and foremost for React Native https://facebook.github.io/react-native/docs/native-componen...
Most developers don't consider accessibility at all because they don't need it themselves. But there are millions of iOS and Android users who do need it, and they might be thankful that you've made their life easier with your app.
Following platform standards makes things easier for users. Users don't care if your app has distinct graphics.
https://github.com/facebook/react-native/blob/master/Librari...
if (color && Platform.OS === 'ios') {
textStyles.push({color: color});
} else if (color) {
buttonStyles.push({backgroundColor: color});
}
Generally speaking, UIButtons have important semantics that are easy to miss if one just reproduces the appearance using custom graphics. The same applies to other standard controls too.
That has been my experience at least, every time we changed something from "our" way to a more default platform way, we've seen better metrics and retention across the board. We even try to avoid platform specific things like swipe to delete etc., because the general user does not use those features, even if you "teach" them in the onboarding.
This doesn't mean that you shouldn't style your app etc to give it an identity, and there's actually a lot of room you have even when sticking to default elements.
As a user, I don't want your app to look different from all my other apps. Your app is not special enough (probably). Why go through he hassle of dealing with widgets that look and behave differently all the time, when you can just find a different app that doesn't do that?
Now, I'm not saying that everyone is going to be that irked by it... but it's definitely not an unpopular sentiment.
I don't think anyone will have a hard time understanding how to press a button just because it looks different than system default.
But for the most part, it's not about the difficulty. It's just an eyesore. Kinda like that one house in the neighborhood that has bright red fences, when everyone else has green. It might even be a very pretty bright red, but...