My own opinion: the show is structured as a “whodunit”, but in reality it’s a character study. Viewers infer different themes based on the characters, but I actually think it’s simpler than that. I think it starts with the kernel of these eccentric characters, then the characters are pushed through escalating scenarios which reveal their true natures. Sure there are themes that develop, because out-of-touch rich people interact with the people who serve them. And the scenarios they go through do knit together into a sort of plot. But in reality, we’re just watching a snapshot of these characters’ journey.

I can see where the structure would lead you to think that you should be looking for something to happen. For me, I looked at it as simply a way to get into the character journey.