Is there a reason to teach sectioning elements?

Today we discussed sectioning elements with my colleagues here at the University of Applied Sciences in Amsterdam. Some of them really like the idea, they really understand the theory behind them, and they want our students to really understand this as well. And now I wonder: do designers (or web developers) really need to understand these rather complicated semantics? And if so, why exactly?

We were discussing articles and sections in particular. I think I understand the difference between these elements, but I find it rather complicated to explain. My students find it really hard to grasp these concepts. They wonder: do these elements actually do something. If we replace them with a div, do people who visit our website get a different user experience? As far as I know, it doesn’t matter.

There are other semantics I have no problem explaining. The different elements in a form, for example, are more than just a concept: they actually change the user experience. Adding a label to an input significally enhances the usability. That’s a real humane reason to use semantic HTML. Which makes it easy to explain, it is not just theory.

But articles and sections don’t have such a real effect on browsers, and on assistive tech. They have the same effect as a div, right?

The original idea behind sectioning elements was brilliant: we would finally be rid of numbering heading levels. But since no browser or screenreader supports that idea in practice, is there still a reason to keep on using them? Or can I just tell my students that it doesn’t matter. If you really understand the use cases of articles and sections, go ahead and use them. And else, just use a div.

Or is there another good reason that I don’t know about.