I tried a few documents and got the same result (ie. each line being treated as separate paragraphs), but was able to find that the fed FOMC meeting doc[1] actually worked properly, but only on adobe acrobat. It was still screwed up on pdf.js. So I guess the format itself technically supports it, but implementations rarely do it properly.
[1] https://www.federalreserve.gov/mediacenter/files/FOMCprescon...