Since then PDF has become more sophisticated, handling metadata, tagging, and embedding media. It's been a long time since Postscript has been "the universal language for graphical and printed work".
A shame, since Postscript is fun.
Not exactly. A PDF is generated from PostScript, as noted in the article:
"A PDF file is a static representation of the result of executing the PostScript file on a single occasion."
A PDF is a more compact version of a PostScript file - we could call it compiled PostScript, to use a term many on this site are familiar with. Just as a compiler has many output options, distilling PostScript can result in many different file sizes and levels of quality. (Check out the Distiller output settings.)
The main difference between the two is that PDF is a declarative definition of the page whereas PostScript is a turing complete language. You can write a PostScript ray-tracer which will execute on the printer itself something which would never be possible in PDF. On the flip side, PDF is far more efficient as an electronic document format.
That's actually not true. There's LOTS of PS files in workflows in commercial printing -- I know because I write software for the print industry.
Its true PDF is often replacing the PS file but these are NOT without their own set of problems.