Comment by PostOnce

Some of them are, most of them are standard typesetting, which you would think would be all the easier to OCR, due to the uniformity.

But because you're curious, there are some fairly famous handwritten books that maintain their handwriting in publication, my favorite being: https://boingboing.net/2020/08/31/getting-started-in-electro...

Old manuscripts are another one, there are a LOT of those. Is that handwriting? Maybe you'd argue it's "hand-printing" because its so meticulous.