Back in the old days (1999) web design was similar to creating an ad for a magazine or newspaper; the fancy web sites might have had videos or sound bite similar to TV or Radio. Now, web design is more like a video game or interactive movie. All the content that was needed back then is still necessary, but the planning, concepts and arrangement of the content has change. Plus, web sites are about user interactions and functionality.
All the visual concepts are important. Getting the fonts, colors and lay out of the written content to go with the shapes, spacing, images, icons and video of the graphics is imperative to sending the right message/feeling to the user.
Functional elements will give your users the best possible experience. Navigation can be improved through multiple user interactions (scrolling, clicking, typing, text to talk, etc.) and using cross device compatibility will insure correct sizing for all devices. Web animation (wiggling image, like button) keep visitors engaged. Site structure and speed will determine the user experience (UX) and search engine optimization (SEO), a slow website can deter a user from returning. A haphazard structure can lose visitors and crawlers (automated bots that search websites) resulting in poor opinions and site rankings.