I've finished read the Novel today and honestly it was okay, not really good and not that interesting. I was skeptical reading this manga at first but it really exceed my expectation making it more interesting and more engaging with the characters, Philia's face is really funny too unlike the novel that mostly word so it can't convey the same. Ch1 was original that is not on the novel, Ch2 and 3 does exist on novel but it was not as good as this manga. ch4 is half original where there's no the maid and butler PoV on novel
tldr: manga is way better than the novel