In photoshop, why can't I press delete after the pen cutout has been created and the selection is reversed?

In photoshop, pen matting creates a selection area and then presses the DELETE key. It is not impossible to delete it, but it is actually deleted, because there is a copied background, which creates the illusion that it is not deleted.

1, as shown below, use the pen tool to pick out the five-pointed star in the middle.

2. Copy the layer, as shown in the figure below:

3. Use the pen tool to load the five-pointed star into the path, as shown below:

4. Right-click Path-Create Selection-Reverse Selection, as shown in the following figure:

5. Press the delete key to delete, as shown below:

6. If you fill the background layer with color, you will obviously see the effect of deletion, as shown in the following figure: