(1) I think there is a huge group of people on this site who are looking for quick, cheap thrills. They look for odd premises and need large amounts of fast paced action. Story complexity and or quality is secondary to the intriguing premise.
(2) There is a reader subset that actively wants sexual content in their stories. Like they need the Girls Love and Boys Love to be explicit.
(3) I've noticed a lot of people like stories with a power tripping main character that constantly grows stronger, builds up an army, gets people to join their party, conquers this and that, etc. Sometimes the reader base wants LitRPG style another reader base doesn't care.
(4) I'm pretty much sure that the majority of people can't stand a submissive MC (which is understandable because they don't really drive plot and seem too naive to connect with), and that a lot of people want a dominant AF MC even if it doesn't make sense. Some of these stories have some ****stain loser go to another world for whatever reason and suddenly they are serious about life and become a hero in seconds. (I think stories with submissive MCs could work, but the story's premise/plot would have to be built around it in some significant and interesting way.)
When thinking of gender bender stories
I believe there are two very distinct readerbases with a pretty small overlap... The ones that ship FxF and the ones that ship FxM.
Yes. I have written a GB story like this and it's a war. My current GB MC is stirring up a lot of dust in my readerbase. My story hasn't even properly gotten anywhere yet and people NEED to know whether it's going to be FxF FxM or whatever else. Writing romance is hard when it's taken seriously, especially with a messed up GB MC like mine. Some stories I've read on scribblehub are like, FxF explicit licking in 5 chapters flat, I can't call that romance. And although my story does have romance and relationships in it, that isn't everything my story will be about. I'm wondering if a lot of scribblehub readerbases are very narrow/specific with what they want to read and they want those quick thrills. This all reminds me that I really need to write more ...