I think you may be underestimating the fact that many people have been writing CSS for well over a decade now, and that it has evolved considerably since they first read a web development tutorial. If you've not been paying close attention (or not been able to), there are many things that will have passed you by.
It's a blessing to learn css fresh today, in as much as it's a curse to still have practices from ten years ago still lodged in your memory.
GP is pointing out the parts that haven't changed at all, and are old (over two decades), simple, and common enough to be considered basic knowledge. I had the same reaction to those and one or two others.
Now if this was someone relatively new to CSS I'd understand, but the opening paragraph establishes how long this person was around. Padding-vs-margin in particular was necessary knowledge to do good layouts back in those earlier days (less so now only due to flex and grid, which aren't on here).
> GP is pointing out the parts that haven't changed at all
Doesn't read that way to me:
> These are things that you learn in a first week of doing web development tutorials.
Sure, padding vs margin isn't exactly new, however `display: inline-block`, ::before and ::after, rem, ch, and :nth-child() certainly weren't in the old html4/xhtml and css2 guidebook that got me into web development!
To add, I think another post by the same poster on this HN post proves the point that they're not dismissing individual parts, but rather disputing (or sorry but trolling) the article as a whole:
> I think (hope, really) that gp is just one heavy "/s". The knowledge presented in the article is so basic that it is hard to believe that a person who does html for two years and six figures doesn't know these. As for the article, I fail to see any reason for it to exist beyond cheap media presence. Or maybe I should start a blog, because I'm not even halfway too.
It's a blessing to learn css fresh today, in as much as it's a curse to still have practices from ten years ago still lodged in your memory.