In the end, almost everything has a soap opera in it somewhere. People have a hard time processing stories that don't have a soap opera in them somewhere. For some people it's just impossible. There's really only a minority of people who are interested in stories that have no personal relationship stories in them at all.

That's not to say that the parts that aren't soap opera aren't meaningfully different. I disagree with the reductionistic claim that "everything is just a soap opera in the end", and leave it to the reader to determine whether or not the original link is making that mistake.

I would say it's more like salt in cooking for the vast majority of people; they expect a certain proper amount and trying to engage a normal human's taste without it is an uphill battle at best. As a result, across a wide variety of genres and styles, you'll find soap operas.

(I use soap opera as a bit of shorthand for things focusing on human relationships a lot. Soap operas tend to focus on the romantic end more than average, so the embedding is not quite perfect. But I use "soap opera" as the shorthand here because they are one of the more pure embodiments of the idea, because they are basically nothing but human relationships churning and spinning, with generally not much more going on. Yeah, a couple of them have a more exotic framing device, but all that does is move them slightly off the center of the genre, not really change them much.)