Based on that limited knowledge, it seems to me that Lois & Clark gets the credit of swinging the emphasis from Superman to Clark Kent as the "real" identity, and making Clark more engaging and interesting than Superman to boot. (Whereas Smallville's contribution to the overall myth was the reinvention of Lex Luthor, not something quintessentially new about either Clark Kent or Superman.)
That's true to some extent, although Smallville should get credit also for being the first truly in-depth exploration of Clark Kent's formative years. Other versions, such as the Superboy comics, still made Kal-El the "true" person and Clark the costume. Lois and Clark may have been one of the first times that Clark Kent was shown to be an interesting person, but Smallville is the first time we see just how he grew into this interesting person, thanks to the way he was raised, and other factors, including his friendship with Lex Luthor, which is, as you say, Smallville' s other major achievement, including the subtext that Clark himself, in keeping his secret from his best friend, contributed and helped create the evil Lex Luthor of the future.
no subject
That's true to some extent, although Smallville should get credit also for being the first truly in-depth exploration of Clark Kent's formative years. Other versions, such as the Superboy comics, still made Kal-El the "true" person and Clark the costume. Lois and Clark may have been one of the first times that Clark Kent was shown to be an interesting person, but Smallville is the first time we see just how he grew into this interesting person, thanks to the way he was raised, and other factors, including his friendship with Lex Luthor, which is, as you say, Smallville' s other major achievement, including the subtext that Clark himself, in keeping his secret from his best friend, contributed and helped create the evil Lex Luthor of the future.