Note that opinions differ on this. Personally I think semantic HTML is nothing but meeting-bait. If you try to be diligent about it you end up in discussions and meetings around whether a certain element should be a figcaption tag should be used or aside etc... And at the end of these types of discussions, regardless of the outcome, nothing that has any actual effect has been changed. It will make zero practical difference whether you use semantic HTML or not. The only thing seemingly affected are imaginary mobile devices that render <nav> differently than <div> or imaginary screen readers that can't read text unless it's in a <figcaption> tag.
It kind of sounds like saying: "Why should I learn math, I will never use it anyway." It might be true, but that is not a good excuse for not learning it. And it is not like using semantic HTML is in any way more work or something, it at least has the benefit of being easier to read and thus maintain.
That's very different. Because there are circumstances where not knowing or applying math is a barrier to accomplishing something. Saying "Why should I learn math, I will never use it anyway." means you're banking on the odds that you will never run into those circumstances.
However when it comes to semantic HTML there is no circumstance where you are unable to move forward because you used <div> instead of <figcaption>.
In fact thanks to the sometimes ambiguous descriptions of which semantic tag is appropriate you may find you used the wrong semantic tag which is arguably worse than not using a semantic tag at all.
And at the end of the day after carefully cross referencing and/or memorizing which semantic tag to use throughout your markup zero real world, practical effect has been gained. Only theoretical gains and memorization for memorization's sake.
It sounds like to be save one should only use <div> and <span> tags, style them with CSS and forget about semantics?
It is obvious to me that this is the wrong approach. And I have never said he should use <figcaption> I said he should use appropriate HTML5 tags. If something is obviously a header, use <header> if not, don't. But building everything out of <div>s like it was in his first example code is just making it more difficult to read, there is no gain in just using <div> for everything.
