This issue starts with a detailed list of reason with to use PDF files instead of Web pages.
There are interesting thoughts about infinite scroll:
PDFs are page-oriented. This is another fundamental freedom – to know unambiguously which part of the document you are looking at. Compare to infinite-scroll HTML pages which are disorienting by design. This may sound trivial, but seriously: with infinite scrolling, you are fundamentally not in control of the reading experience.
The total word count of the W3C specification catalogue is 114 million words at the time of writing. If you added the combined word counts of the C11, C++17, UEFI, USB 3.2, and POSIX specifications, all 8,754 published RFCs, and the combined word counts of everything on Wikipedia’s list of longest novels, you would be 12 million words short of the W3C specifications.2
I conclude that it is impossible to build a new web browser. The complexity of the web is obscene. The creation of a new web browser would be comparable in effort to the Apollo program or the Manhattan project.