[SkiFire13]

PDF was designed to look the same on any device/viewer and that's something that HTML/CSS/JS will likely never be able to do (every browser does things slightly different!). HTML also lacks good support for embedding resources in a single file and is much heavier to display (try coding a whole HTML + CSS + JS engine vs a basic PDF/A viewer!). Moreover HTML/CSS lacks all the typesetting features that Latex/Typst support out of the box.

But anyway here's a challenge for you: take some random small document in Latex/Typst and try converting it to HTML/CSS/JS while keeping the same layout and visual feelings. Make it a single file you can share with people and try seeing if all browsers display it the same way.