Instead of saving them as PDFs, I started saving web pages using a Chrome extension called Single File [1] (after testing it, of course).
To my dismay, some saved files (.htm extension) didn't open when I wanted to open them.
So I'm glad people are discussing ways to archive web pages while that reproduce the original page faithfully.
[1] https://chromewebstore.google.com/detail/singlefile/mpiodijh...