Why not many Korean WS after Bang So Hyun perform well in badminton world? We still can see a lot of MD and WD of Korean, but not WS, I think INA regeneration better than KOR WS...
I have the opposite opinion
After Mia left, Head to head WS INA vs WS KOR, Korea was better
I didn't have record Maria against KOR WS,
Firdasari never win against Hwang Hye Youn, Lee Hyun Jin, Seo Yoon Hee.
Bae Youn Joo looked promising as future WS, sorry I say that she better than INA future WS.
Better h2h WS INA only on "older" players vs "upcoming" WS KOR, like Lidya Jaelawijaya beat Jun J.Y. ON SC, Ellen Angelina beat Lee K.W. or Silvi Antarini ever beat Jun J.Y.
Ra Kyung Min, Lee Kyung Won were good single players, maybe they were best KOR WS on those periode.
Ra K.M., Lee K.W. and others WS KOR moved to focus on WD & XD, it was their choice. They saw bigger chance on doubles.
After Mia Audiana,
only Maria who compete in high level of WS. Jun Jae Youn took a long time absent because of injury.