The Gutenberg Design Principles do a great job of explaining how the new WordPress editor has been designed to function.
The basic ‘Goal of Gutenberg’ is mentioned here:
The all-encompassing goal of Gutenberg is to create a post and page building experience that makes it easy to create rich post layouts.
There is also a clear Vision Statement that ends with the following statement:
Ultimately, the vision for Gutenberg is to make it much easier to author rich content. Through ensuring good defaults, wrapping and bundling advanced layout options blocks, and making the most important actions immediately available, authoring content with WordPress should be accessible to anyone.
