I can imagine doing that in Pandoc Markdown, but only with extensive use of raw LaTeX code. Most of the above doesn't have a direct equivalent even in richer Markdown dialects like Pandoc.
Try justifying text on a relatively narrow column in HTML, and then try it with LaTeX. There's a world of difference in readability between them.
LaTeX is techniques and heuristics from hundreds of years of typesetting for print, codified into a program.
HTML is at most 29 years old, and has only supported typesetting of any kind for a fraction of that. What typesetting capabilities it supports are designed by committees, and its primary purpose has always been screen display, never print.
In the simplest/best case, LaTeX will simply produce nicer-looking results for print. In more complex/worse cases, LaTeX can do things that HTML in a browser can't reasonably do at all for print, even with CSS.
> And since "print" very often means a PDF that's also available online, has there been any progress on tagged PDF support in pdflatex or a similar tool? This is important for accessibility.
I can't answer this question directly because it's been a while since I attempted such a thing, but this is largely what I was joking about with the "the project is going down in flames" bit in my previous post. If you are concerned about accessibility, targeting a proprietary format that resists parsing for text-to-speech or fragment translation and doesn't support variable-width lines for screen readers is a bad idea. Tagged PDFs are really just a hacky attempt to fix the problem: HTML was designed with accessibility in mind from the beginning (though admittedly HTML/CSS/JS as used by modern websites do a very poor job of providing accessibility). Maybe there has been progress in adding this to pdflatex, but it's still a bad idea.
Typesetting my thesis in LaTeX (physics, 2000) was an amazing choice. I could hardly modify anything (it is doable but requires a lot of work and in the meantime you learn that the default is better) so I was left with the content.
I knew that it would just work and took from me all the philosophical sufferingbof choosing such and such fontvsize for the title of adjusting margins, or placing a graph.
And since "print" very often means a PDF that's also available online, has there been any progress on tagged PDF support in pdflatex or a similar tool? This is important for accessibility.