I don't know if there's an answer, but I do know that even the existence of someone as phenomenal as Kim doesn't make Kwan any less splendid to behold. She will always be a magical skater to me, as Kurt Browning will always be also (and he had no Olympic medal of any color). I actually love threads like this, though, because it gives us all a chance to examine great skaters and hear new insights from one another.
Kwan in her prime sure as heck could have beaten all the current roster of Americans, anyway, triple-triple notwithstanding, CoP notwithstanding. She's make the U.S. look good in any era. But what she did achieve in her era, and what stands now and forever, is that bewitching amalgamation of mental toughness, meticulous technique, musicality, and artistic interpretation. Will I ever stop getting gooseflesh from her best programs? Well, I haven't stopped getting gooseflesh from Janet Lynn's, and she mostly did only double jumps. Why would Kwan's wonders pale on me?
This is not to take anything away from YuNa. She's a grand jumper, but she's not just a jumper by any means. As Kwan was Lori Nichol's muse, YuNa is David Wilson's. She expresses music beautifully and certainly equals Kwan in mental toughness.
Maybe I'm greedy, but I'm thrilled to bits we have them both! And our marvelous Mao Asada in the bargain. Who's better? Who cares! Is a diamond better than a sapphire or an emerald?