>>283240782
Because of top of being a lot harder to write because >research (most authors can't even be bothered to play a video game before writing vidya isekai slop, do you think their ADHD brains could handle actual historical texts?) stories about pre modern lesbians will inevitably be either dark, not all that lesbian, profoundly unrealistic or involve a lot of male partners. Or somehow all of the above.
Just look at picrel. So she's apparently not a real prostitute under contract, but she's... Not aware of that? We're supposed to be able to cope that she only fucks women, but that's not really realistic, isn't it. This doesn't let you avoid the male partner plot completely either because of course there's an arranged marriage, and on top of that there hasn't been any fucking in almost a dozen chapters because lesbian prostitute was only the (unrealistic) hook in the beginning, the actual story has to be more solemn if it wants to give off an air of realism. Because why even write historical when realism is not a goal.
You may mitigate some of these problems, but at its core that's what historic yuri is, and it's a rather niche genre within already a niche.