Long articles with many sections often discourage users from reading. They start reading and usually leave before reaching half of such articles.
To avoid this type of user experience, I recommend to group each section in your article into a collapsible tab. The article reader then will be able to digest the text in smaller pieces.
The Collapse Text Drupal 8 module adds a button to your editor. With this button you will be able to create collapsible text tabs with a tag system similar to HTML.
Read on to learn how to use this module!