Just amusing that after all these decades this is still not a solved problem. Why can’t the browser just translate the PDF into HTML and display it normally in a “virtual” webpage? Make it pdf:// or whatever.
On android I have to use a firefox fork called iceraven to be able to install pdf.js extension to use mozilla's own pdf.js to load pdf's in my tabs. Afaik, there's no other way to do it.
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.