The simplicity of integrating with a CSS framework is provided by the new template system, Twig, and the asset management system in Drupal 8. The usage of Bower is optional, but it is usually a preferred method for managing frontend dependencies and can be used to keep third-party libraries out of version control.

Although it may be a task to add each component as its own library and attach when specifically needed, it ensures optimal asset delivery. With CSS and JavaScript aggregation enabled, each page will only have the minimal resources that are needed. This is an advantage when the entire Semantic UI minified is still 524 KB.