Started hobby collecting old books about 2 years ago, mainly classroom math/science/history books. Most of them are from 1800's - 1910. Quickly notice, despite the stilted writing style, it's much easier to understand concepts from these old books compared to their modern day equivalents. Information is concise, examples/explanations are not midwit word problems or analogys, amazing pictures and diagrams. My largest epiphany of how fucked books are hits me when I get hold of a 1800's medical book called "A text-book of human physiology" by Flint, Austin. It has amazing in-depth explanations and detailed gorgeous hand drawn diagrams, you can't find anything like this online or is most basic medical books.

WTF happened? I realize information has been "dumbed-down" or even censored but still I never knew it was to such a great extent.

Online Archive of "A text-book of human physiology": https://archive.org/details/textbookofhumanp00flinuoft/page/776/mode/2up