Recently, another version of Justice League was released. This version, dubbed Zack Snyder's Justice League, has been characterized as a director's cut of the original, suggesting that most of the major plot points are the same, but it also has been described as a soft remake of the film. On a first watchthrough, many things are clearly different: the introduction, for instance, or the expanded role played by Darkseid. Indeed, as indicated in the comments, a good three-quarters of the film consists of entirely new material.
Given that there have been such drastic changes, how much of the plot has been kept? Which elements have been retained from the original?