[0]: https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
[0] Obvious problems, like unplayable, etc. Minor problems (chroma placement error, transfer function, etc) seems to occur very frequently.
That's one of the reasons these days there's a tendency to use text-based representations like JSON, but of course anything size-sensitive such as images and movies is still generally binary.
What I really don't understand is Acrobat Reader. It has a "Protected View", which is the first WTF - .pdf-s are read-only, so there should be absolutely zero active code running anyways. What's the next, much bigger WTF WTF WTF is that you need to exit protected view to print the document.
How can the program read and render the document on screen, but not print it?! How is this even possible?
PDF is an old complex format with a lot of features used in a lot of special cases that go light years beyond looking at a simple text file. It's the reason for all the issues, but keeping it useful as it is and magically waving away all issues is not really easy.