How has the developer focus shifted due to the increasing scope of modern UI toolkits?

Answer

From worrying about drawing a disabled button to correctly passing the state variable causing the disabled state.

Modern toolkits absorb low-level details. A developer today rarely worries about drawing primitives (like a disabled button's pixels) and instead focuses on managing the application state that dictates how the component should appear.

How has the developer focus shifted due to the increasing scope of modern UI toolkits?
inventionsoftwareinventorInterfacetoolkit