Atlantis is pretty much a universally beloved myth: its splendor going back centuries at a time. The motif of an advanced civilization that flew too close to the sun (another Greek parable) is not only mysterious but relatable, as humanity often fears becoming victims of their own success and always enjoys a good cautionary tale. Stories of Atlantean origin have been adapted by pretty much every media arm in existence, from Warner Bros., to Disney, to Lord of the Rings author J. R. R. Tolkien.
You can also add Ubisoft to that lengthy list.
Source: Destructoid Review: Assassin’s Creed Odyssey: The Fate of Atlantis – Episode 1