Scholars generally read the Sumerian King List as a work of political argument rather than disinterested record-keeping. Its central premise, that legitimate kingship exists as a single office passed in strict succession from city to city, served the interests of whichever dynasty a given copy's scribes were writing for, most plausibly the Ur III dynasty or a closely related early second millennium BCE power asserting precedence over historical or contemporary rivals whose own claims to kingship the list simply omits or subordinates. That the surviving exemplars disagree with each other, in which cities and kings appear, in what order, and with what reign lengths, is itself evidence for this reading: a passively copied historical record would tend to converge across copies, while a document actively serving different scribes' different political purposes would not, and does not.
The text's significance for the study of religion sits mainly in that opening claim, that kingship is a gift descending from heaven rather than a human institution, and in how it handles the flood as a hinge point separating a mythic antediluvian age from a more historical one, a structure that invites comparison with flood narratives elsewhere in the ancient Near East, including the biblical account, without this record asserting a direct line of dependence between them that has not been independently established. Modern study of the list, beginning with Thorkild Jacobsen's foundational 1939 edition, has focused heavily on using its later, more plausible entries to help anchor the chronology of early Mesopotamian history, a use the text was never composed to serve but is well suited to nonetheless, once its mythic and political layers are read as what they are.