This is a known thing.
You even have successful idols who talked about it and who said that ff and fs made their life terrible (Heechul, Ren, Hongki, Jokwon, even Amber....), but fans dont care and continue on insisting on fanservice and fan-fictions.
The above people all ended up with psychological problems bc of it. They couldnt interact normally with friends or anyone bc people will always see sexual things in it and start to talk about "relationship" and stuff.