
Honestly, MC here just has as much of a shitty life as some of the other MCs. Though in her world, she already grew up and left behind that source of shittiness(her family) and lives by herself as a grown adult. But when you're thrusted in such an unfamiliar place, you'd be missing just about anything even if it's the source of your sadness

Emotions are weird. That's why. Also, this new "better" life of hers isn't any better anyways. In the first place, it's not her body to begin with and she finds something wrong with that, second--nobody likes her there, excluding her maid and dad cuz they loved Eris, not this stranger in her body. Also, She's doomed to die in that place and she cannot even change her fate by trying to divert the plot because the world will set it back up. Just the thought of having your destiny set in place and you already know how it's going to be will seriously mess your head up.
Compared to her previous world, there-she can actually take control of her own life and find happiness on her own without others getting in her way. She's able to escape and cut off that source of unhappiness. Also social statuses, while still a thing doesn't depend on the caste system on where She's from so She's able to act more freely. Also--technology and life expectancy, her original world is way up there. Sure the new world has technology magic but it's limited.
i like how her feelings are actually realistic. the FL's in other isekai forget all about the fact they're in a different world and don't even really attempt to go back or even feel bad about it lol