Isn't that exactly what browser PDF viewers (e.g. PDF.js [0]) already do?

[0] https://mozilla.github.io/pdf.js/

I thought of making something like this once. Then I started to look into the PDF standards and realized it's one of those things that you're thinking, why has nobody done this? Then you start looking into it and you realize why nobody's done it. The task would be monstrously difficult if you want to cover all the things that can be in a PDF.

PDF is a beast. It's a ridiculous file format. There's a reason why even after all these years, reading PDFs still kinda sucks.

I mean, that sounds basically like what PDF.js is. It’s not static, though.