Do they really need to make the villainess a tragic girl that isn't actually a villainous???
Fck that. You are the daughter of a DUKE!!! A DUKEEEE!!!!!. And that crown prince is just that a brat! The king and queen can just make another one.
How embarrassing for the royal family to have a crown prince with no manners and brains
Look, you need to understand one super important thing...
She is supposed to be a villainous... but the author of this manga doesn't want her to actually be a villainess, so they give her the ending without any of the logic...
In fact, in 99% of these stories where they either transport to the villainess' body or get close to her or something, they don't actually fit the role of a villainess and are technically put in the roles of a heroine...
It's just lazy writing done so that the MC can have world knowledge..
So can you blame the prince for being stuck in a weird role where he needs to have a villainess but the author doesn't want the villainess to be one so he could write her as his heroine???