Native plugin over C#

Considering I can perform an action via C# or using native plugin, and despite the fact that using C# code is easier since they would do it all in one line, would there be a benefit of using native code?

One example (not sure it is a good one but it is just for the sake of making an example):

I want to make a screenshot, I can use:

Code (CSharp):

1. Application.CaptureScreenShot(path);

now I can also do that using xCode for iOS, would there be any particular benefit to create a C# wrapper over native code? Performance mainly.