It looks like the author used Tesseract, a traditional OCR image with lineage going back to HP flatbed scanners in the 1980s [1]

Obviously, it's been improved a lot since then - but traditional OCR is mostly about black text on white backgrounds. Or at least, the text being high-contrast relative to the rest of the document.

Light gold text on a white background, while there are black splatters? That's the sort of thing it would struggle with for sure.

[1] https://static.googleusercontent.com/media/research.google.c...