🎯 So, who is responsible for binding the object (ViewModel) to the View?
✅ The Developer (or MVVM infrastructure) is responsible for setting the DataContext — not the UI Designer.
The UI Designer designs the UI using XAML and defines the binding paths like:

But these bindings won’t work unless the ViewModel is assigned to the View’s DataContext — and this is typically handled by the developer.

🔧 How the Developer Sets the Binding (via DataContext):
Option 1: Code-Behind (commonly used in smaller apps)

public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
this.DataContext = new MainViewModel(); // 🔁 Binding happens here
}
}

Option 2: ViewModelLocator (preferred in MVVM frameworks like Prism or MVVM Light)