lol the comments. The author actually draws well in his art page, they are a cover artist and the girls there are normal size and obviously they know how to draw women.
Why does he draw the female like that?
Many options. There is no black and white thing. Probably the editor reccomended for an ADULT (+21) comic to size up to make it more popular and give more contrast with other girl characters. And probably was a good idea, the comic has 40 million female viewers and downloads in the site. In the webtoon world were everyone is competing, the artists need to push up to deliver a weekly comic (almost imposible to fullfill the schedule).
If an editor of an adult comic tells me to do big boobs, big dicks and a refrigerator as a male lead and promises me 1 million dollars, probably I will do it too.
Other option. Is it his own fantasy? maybe, like many other male and female authors, but for sure this manhwa is not for men, women are the main target and looks like the majority of them love big boobs too (I found funny korean girls really praised on her body and are thirsty for her). If that's the case, the author loves Haesoo and doesn't hate her.
Would it be better to be a manhwa rated R15 (for teens) with no adult content and a normal body? I prefer that way because I get tired of smut. But it would be hard to make it popular with teens when the main protagonist is 33/34 years old. (for a teen, someone in their 30's is ancient, specially if it is a woman) The main consumers are adult women or josei type who are more into wattpad stories/cinderella plot (not good but gives a lot of money).
If girls love this style, it is ok, they can continue enjoying this and thirst on her body and straight girls can thirst on the bodyguard, father or ML (there are many options to thirst on)
If other girls are not fond of this kind of Style (like clamp and others) it is ok too and they have other options to read.
Then you'd know that most women (every women in my life that has struggled with this and many more that u can probably find on social media) fucking hates it. Bc they're always in pain. The girl in this manhwa doesn't have that. She isn't built like those who have biology making their lives difficult. This character is built like some weird fantasy of the artist (and apparently tons of women, idk why the fuck

I tried reading this bc it's popular but I literally can't- she doesn't even look like a real person why is she proportioned like that