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.

And that's false as of 1987. With the reboot of Man of Steel and whole runs of other comics dealing with Clark Kent and Lana Lang in Smallville. As for John Byrne regarding Clark Kent as a 'false person', that's the diametric opposite of the whole theme of the MOS reboot.

MOS also predated Lois & Clark.