This post brought to you by me really, really wanting some nice long kpop fics to sink my teeth into

Does anybody have any thoughts on why certain fandoms seem to inspire more longfics and others don't? Moving from Buffy fandom, which had tons of multi-chapter fics, into kpop fandom, which has VERY VERY FEW, has been quite an experience for me. Infinite fandom is blessed with a multitude of really excellent short fics, but I really miss the feeling you get when you read a longfic, where you are totally immersed in that world, where you really go on a journey with the characters. And I can't help but wonder why there aren't many longfics (the ones that exist are usually not very good at all). What is it about a fandom that makes it more likely to produce longer works than other fandoms?

I for the life of me can't figure out what would make fandom culture be so different.

What are the fandoms you've been in that have many longfics? What are the ones you've been in that seem limited to short fics? And do you have any ideas on why they were that way?