Think of it like self insert fanfic. Once they know the ins and outs of a story they believe they can improve it with their touches by inserting themselves into the mc's role in the story.
It's a heavy amount of delusional belief.
Which honestly makes no sense about trying to steal this girl sponger husband who basically owns nothing. Where the wife is the rich one. Oh push out his wife? Okay wife leaves and takes back all her dowry? U live with poor husband now. Idiot.
The way that Su Luxia get pissed everytime that she hear about the original host's waist line. You would think that she had PTSD from when she had to deal with problems like that before she became who she was.