Any good romance is going to be both realistic and unrealistic.
Realistic because good art, even just a film that isn't too serious, hoas to get at something true to be worthwhile. Where you go "ah, yes, that's how that is".
But romance by definition is unrealistic. It doesn't mean sitting at the table with a rose and feeling lovey-dovey, it means it in the sense of romanticism. That is, an artistic movement that concentrates on subjective experience, and emotion. A story that is romantic doesn't have to be realistic in every way.
So the story about the author and cleaner who don't speak the same language and seem ver different is about how we can connect with someone in a way that transcends language and other seeming barriers. In that instance, it's about the little things, showing consideration for the other, a kind of quiet domestic harmony, watching on a daily basis how someone is in themselves. It's not a realistic situation, it's over the top, but the basic idea is true, there is something powerful about that kind of connection and it can reveal things that talking distracts from.
Or the sex pest - yes, we all recognise this guy. And also that his idea seems crazy, to find a girl in America who will like him because of his accent. But on the other hand, we all know there is a bit of truth to the idea that people respond to superficial things like accents - it's why they are used in films to make characters more or less likeable. So just his accent could change perception of him in a different cultural context, in this case from a sex pest to exotic. The over the top way it happens allows us to laugh at how absurd that is. Not just about him - he's not real - but about human beings in general and attraction and how illogical it can be