Manhwa with this theme aren't rare, it's not like they suddenly just appeared now and there was no such thing before. You just happened to encounter two in short time.
Personally I terribly dislike those where ML basically raised FL(grooming), but I don't mind those where a couple becomes two not blood related step-siblings/relatives who met at a later age and never considered each other family. This also applies to reincarnated FLs, since they didn't know ML from the beginning and didn't consider them family, so in that case it's possible to develop romantic feelings.
To be truth I don't remember even one manhwa where ML&FL are truly blood related, It's always not blood related relatives. You remember even one like this? If there is then it's really sick.
I never said it hadn't been around? I've seen it before. I don't remember the title, but the one where the FL is reincarnated and into a half sibling with the ML and they don't grow up together but still get together romantically.
And I generally the ones I've seen where they meet at a "later date" as you say, they're still children that eventually fall in love. The second manga I mentioned, they meet as child and teen. They probably obviously fall in love when they're teen and adult or teen and teen, but that's still time RAISED AS SIBLINGS together. (And to play the other side, I do not know how they're raised but it doesn't change much for me)
And the first one I mentioned she was ABUSED by her family (father's brothers and servants) but in the end she still gets with the father??? She does get body swapped for 10 years, but when she gets back shes still mistreated.
And if my memory is correct, I have seen a one where they are blood related, but it's been awhile since I read it so I'll need to find it. So disregard if I can't find it.
Also, I'd like to say that if there is incest fantasy manga I've seen, it doesn't have as good as art as I've seen them having recently. I was just ranting about how disappointed I've been to start reading a manga that has a good premise and art, only to be blindsided by a family member being the main love interest. I get disappointed that there was no other way to introduce a love interest than inside the family.
Of course, I didn't mean that incest stories are a good thing. I understand that you just wanted to complain about encountering something you didn't want and being disappointed that it often has a better art than other "healthy" romance stories. But it would be funny as if only incest stories had ugly art (≧∀≦)
Don't worry I just wanted to join the discussion, I'm absolutely not saying that your point of view is wrong or anything. I am also not fan of stories like this, they are sick, but still it's fiction. When you turn off brain then in some cases incest stories are still a good read.
My favorite comfort manhwa The Viridescent Crown also have this theme. I know I shouldn't like it, but I still like and I can't help it ╮(￣▽￣)╭
Alr alr, what's with the sudden increase of fantasy manga I'm seeing where the Female MC ends up with a member of their family blood related and adoptive. The two most recent in my memory:
-My Body Has Been Possessed By Someone
-The Blooming Violet in the Back Garden
Like and the art is so nice too so I get tricked into thinking it's a classic fantasy manga that I love reading