@Aireael
I think at the very least, if the isekai elements aren't going to be a big part of the plot or there's no cheat, it should be used to explain some part of the MC's personality. For instance, in Who Made Me a Princess, it's shown that the MC's relationship with her father is strongly influenced by the fact that she was an orphan in her previous life. Even though it would be easier for her to abandon her father, who is a tyrant, she can't help but cling to their relationship because she remembers what it's like to be an orphan in her previous life.
I, a Commoner, Was Actually Reincarnated seems to imply that the MC decided to leave her house after remembering what it's like to be abused in her previous life...but you don't need isekai for that. The author could have just said that she had had enough of her family and left and I would have believed it. It's a fantasy setting too so a child leaving home wouldn't be shocking to me. But who knows, this is just the start. We could get more isekai elements later.