>>230726Hii hii, I can give some of my thoughts on this as a little writer / artist...
So, I think there's a couple key reasons. The gap between dark stuff in Written vs. Art is really easy though. Most artists want to draw happy stuff!! Drawing cute girls sad is just so saddening to look at actually... It's not some paragraph you toss together, then go onto the next. It's this sad, crying character of yours staring at you on the canvas. It's hard to bear 💔 just so much happier to draw happy fatties instead!
For the "I'm fat and happy" ending trope, you mentioned the logic that often goes into justifying that as a negative, but I think that logic itself really is the meat of WG stories! That's what is there to be developed by the author and the journey we're going on in the story. For example, we have a cute skinny girl, Skinny-chan, who would never be like one of those other girls, fat hogs scarfing down burgers and blowing up! That initial state of Skinny-chan is setting the expectations and then slippery slopping into them until she's at the end; A fattie like the rest of them with a goofy smile as she eats her next burger wondering why she was ever so opposed in the first place. Yes, it ends at the usual conclusion but every step falling deeper into what the old her hated is a dark, insidious beast consuming the character we once knew. In more traditional literature, they might actually call this 'character death'. Our main character has transformed so dramatically, both physically and mentally, that it is as if the original character is long gone by the end 😱
Again, nobody wants to write a story that makes you actually feel bad. Our main character Skinny-chan can't walk into the bathroom and just stop cold, staring at her own reflection, disgusted with herself, what she's become... Instead, she'll acknowledge what changed about her. Be embarrassed or think some sort of a positive about it, think about she'll hide this somehow, or she'll definitely lose the weight soon! A classic is a fun comparison: Skinny-chan is glad at least she isn't as big as Chubby-chan! It's not all that realistic but it's just so much less negative then it'd probably be in real life. And now the reader can read it giggling aloud "Not yet you aren't, Skinny-chan!" It's fun, it's hot, and it doesn't have bad feelings attached that way!
So like you said, the characters may initially be upset with their weight gain, but by the end we're probably going to arrive at fat and happy ending ~somehow~ 😊 This is like a mix of the writer not trying to write an upsetting story and also stories just usually go towards happy endings anyways. But there's some leeway here, with less than realistic-sadness but still a bad ending. Such as maybe Skinny-chan is still clearly mad that she's fat now, but hits us with "Just shut up and get me my next blow-up burger!" - not happy, not super sad. It is still acceptance but in a more "it is what it is" sorta way IMO
But even without getting too much into realistic sad there's definitely some more angles to write WG stories than just that overly happy and accepting route. I attached pics of my poor purple ninja maid, all bummed out that she's became fat and how her fat girl loving boss is going to be so disappointed in her. (Huh?) And my totally delusional pink cutie with her sister who is just coming in to tear her down so she can feel better about her own weight gain she's so upset about. All these zany, conflicting feelings and how they'll react with the other characters is the essential piece of making a WG story, I think! And the WG 🤭
Also, sorry I wrote way too much... hope it's helpful!~ ❤️