During its tenure, the DCEU has not had the most solid array of stories. Movies like Man of Steel, Batman vs. Superman: Dawn of Justice, and even Wonder Woman 1984 struggled with thin plots. Throw in the box office bomb known as Justice League, it became clear the Snyderverse needed to improve.
Source:https://www.cbr.com/aquaman-and-the-lost-kingdom-unanswered-questions/