Why isn't there a default Web. xml file after creating Dynamicwebproject in eclipse?

When you create a new dynamicwebproject in Eclipse, do not click "Finish", in the next there is a tick option (Generate Web. XML deployment descriptor), the selected will default to generate Web. Xml. For example:

After you create the project structure, for example, you see:

Note The structure is: Web. XML is outside the Lib directory and within the Web-inf directory. It seems that the Web. XML is not a problem in the Lib directory.

Why isn't there a default Web. xml file after creating Dynamicwebproject in eclipse?