I prefer writing for HTML4 Strict and publish as HTML5 to take advantage of the concise header and some other tags that have legitimate usefulness. It means that I don't prefer using tags like article, header, footer, section, and aside because, contrary to conventional notions, they are semantically redundant and unnecessary.
I would say that most developers don't bother studying W3C recommendations because they naturally learn on learning mostly from random tutorials and follow their own sets of rules, or they wouldn't embrace things like CSS frameworks and presentational CSS classes so blatantly.
I don't use tags like articles, sections, etc. because all you need to do, when it comes to a fundamental document structure, is to structure your contents with all the right "h" and "hr" tags. "h1" is used only once as the title of the page, and everything follows (h2, h3 under h2, h4 under h3, and so on. It's like an outline with full contents). After that, it is a matter of using "div" tags only where it's necessary to group and style things. But I say, "ONLY where it's needed" because I can also leverage a lot of block-level tags to lay out blocks of things without them some of the time.
"hr" tag is for things like a footer that don't warrant an "h" tag yet still need to be a section of a document. It is NOT about drawing a horizontal line. It is for a semantical meaning. You can render it as a line, or you can hide it with CSS (so it is still there for a screen reader) and wrap it around a div tag to create a little more visually extensive footer.
HTML is for content and its structure, and CSS is for a presentation of the contents in the HTML document. The point of using both is to separate concerns. Your goal should be to write HTML as minimal and clutter-free as possible so you won't have to make any changes in the future when you need to change the appearance of the website. A ton of people will say it is unrealistic, it is not how we work these days, it won't work in a large-scale site, and so on. IGNORE THEM, because I found that the industry is so full of misinformation and the mindset of "newer and shinier, the better" and "Wah wah I dunt wunna luarn, I dunt wunna du hurd wurk" nonsense.
CSS Zen Garden (csszengarden.com) is a bit dated but still a relevant example. It is one of the examples of how separating concerns can be extremely beneficial in the long run. You should take a look and analyze what they are doing with HTML and CSS. You can do what those people did in their time a lot easier now thanks to CSS Grid and Flexbox. So many developers have forgotten the original intent of HTML and CSS presented in the site. We as an industry is now too busy reincarnating HTML3.2 presentational markup mindset with presentational CSS classes littered all over their documents. It's so bad that it makes Word War Z zombies feel like a charming fairy tale. To me, presentational CSS classes are rotten zombies worth shooting down right in their head.