text selections look weird

[YousefED]

I'm comparing different pdf libraries. While pdfmake has a nice API, the following has me a bit concerned.

pdfmake selections
PDF downloaded here: http://pdfmake.org/playground.html

Notice how it looks like all the words are selected "separately". Is there anything weird pdfmake does by default that causes this? Compare this to other libraries where selections look a lot cleaner:

pdfkit
PDF downloaded here: https://pdfkit.org/demo/out.pdf

jspdf

PDF downloaded here: https://raw.githack.com/MrRio/jsPDF/master/index.html

(PDFs are opened on Chrome on MacOS)