Why PDFs are hard to read on a Kindle
A PDF is laid out for a printed page. On a Kindle it stays that page: small text, fixed margins, and zooming in means scrolling sideways along every line. A scanned PDF has no text at all, so you can't search, highlight or look up a word.
An EPUB is made of text that flows. Your Kindle sets it in the font and size you pick, wraps it to the screen and remembers your place.
