> Most large brands throw the UI design patterns of the platforms out the window in favor of their own UI guidelines.

I really wish they would not do that.

The best thing you can do to make your app trustworthy and friendly is to adhere to the host operating system UI guidelines and expectations.

Nobody wants your unique take on the checkbox or textarea please.

They vary in terms of architectural patterns and ui widgets. RN tries to prevent a single interface, but you quickly reach the point where it becomes a pain. You can use Expo to help, but their libraries are unstable.