It looks like Superman and Lex Luthor's dynamic in the DCU is a bit more deep than their fans may have thought. A private thought of Clark Kent's regarding his archenemy reveals how the two are the living embodiment of the nature vs. nurture debate.
They say a hero is only as good as their villain, and when it comes to Superman, no enemy has pushed Clark more than Lex Luthor. For as good and selfless as Superman is, Lex is just as amoral and egomaniacal. Clark and Lex's relationship spans decades, all the way back to their beginnings in the town of Smallville. But despite growing up in the same location, they didn't have the same formative experiences, as Clark had the loving Ma and Pa Kent to raise him, while Lex's father was nowhere near as warm or kind. As the years went on, both men seemed to reflect the values that they were raised with.
Which led to Superboy asking a question that many Superman fans may have asked themselves at one time or another. In Adventure Comics #1 by Geoff Johns and Francis Manapul, a recently resurrected Superboy moves to Smallville to find himself. Before jumping back in as Superboy, Conner Kent wants to understand both of the men he was cloned from in order to better understand himself. Gaining perspective on Superman is easy as he just moves back in with Ma Kent and begins doing the same things Superman did as a young hero. But learning about Lex proves to be tricker. Conner investigates Luthor's old family home and Clark is there waiting to talk to half-clone. Superboy asks Superman if Lex could have turned out better if he had parents like the Kents, to which Superman seriously doubts.
Superboy isn’t wrong about the positive influence of Superman’s parents had on him. In worlds without being raised by the kindly couple, the hero found himself closer to the dark side, as seen in stories like Superman: Red Son or Flashpoint. However, whereas Clark has more often than not been interpreted as the product of his upbringing, Lex Luthor has almost always been shown to be sociopath no matter his personal history. When everything else is stripped away, Superman vs. Lex Luthor is ultimately a story of nature vs. nurture.
Baby Kal-El’s rocket could have been found by anyone, and various stories have explored that sort of concept. From the US government to galactic dictators, how Superman is as an adult has always been dependent on who found him as an infant. Lex Luthor hasn’t received as many Elseworlds-style tales, but of the ones he has appeared in, those that do alter his background still portray him as the scheming genius that thinks himself better than the rest of humanity. Clark isn't wrong that Lex Luthor would become a villain no matter what, but for Superman, he absolutely needed the Kents to grow up to become the DC Universe’s number one hero.