All I can say is girl groups are indeed superior to boy groups.
The BG stans are triggered that most of their faves can't outsell SNSD even with the male advantage and even when they do they still won't be as legendary or loved globally.
Not to mention the sheer talent SNSD has like an A+ actress (YoonA) a respected dancing queen (Hyo), Writers (Seo, Tiffany) and vocalist of the generation (Tayeon).