I don't remember the fandom in fanfiction.net (star wars maybe?) but in my times guys who got pregnant were called damsels or something like that and, with the help of time and imagination, gave birth to the whole concept of omegaverse.
It was more... sweet and romantic. Not all the time but there wasn't so much sex violence. Now the whole experience has expanded a lot with bites, bonding, imprinting, gazes, gama, etc. Like you said, there is something for everyone but the common traits most of them have is: the concept of finding your mate (with or without love) and rut/heat as an excuse to romanticize rape. I suppose it evolved into kind of a fetish. Of course not every omegaverses are like that. People and modern times are starting to point out the wrongs doings and that's good.
I liked this story because it had a religious aspect and mysterious themes, the whole soles and lunas, past lives, but It's also true that this was smut from the beginning so it was to be expected.
This is one of those yaoi that is 90% porn and that is fine. The yaoi world is vast and there is something for everyone....I just find it funny how the entirety of the omegaverse genre was created to justify more mindless fucking. I think that some readers wanted to read about men fucking like actual animals but didn't have the stomach to read actual furry yaoi or those monsters fucking so this was a good in-between: humans that go in heat and fuck for days on end while slurping each others' goo