It seems a bit of an arbitrary choice. For example, Polish has digraphs, but Czech has diacritics, and Icelandic has a couple of additional letters that aren't modified Latin letters.

Old English had four letters that are not in today's US-ASCII, two of which are borrowed from a runic alphabet rather than created by modifying Latin letters.

It's also a bit arbitrary whether a modified Latin letter is regarded as a new character or an existing character modified by a diacritic: take Ø, for example. And there are characters like Æ. And never forget what Turkish did: add dotless i so that ordinary i could then be regarded as dotless i plus a diacritic (though of course it isn't usually regarded that way).

"Nineteen eighty-four" is probably his most famous book, but many would say that "Animal farm" is a better book and that Orwell was best at writing essays, so make sure you've read a collection of his essays before you decide whether he was a good writer!

You're not wrong about Orwell being posthumously enlisted as an anti-Soviet propagandist, but "Animal farm" is beautifully written and makes perfect sense to a reader who knows nothing about (and has no interest in) the early history of the Soviet Union.

I'm fairly sure that the law treats humans and machines differently, so arguing that it would be OK if a person did it therefore it's OK to build a machine that does it is not very helpful. (I'm not sure you're doing that but lots of random non-lawyers on the Internet seem to be doing that.)

Claims like this demonstrate it, really: it is obviously not copyright infringement for a human to memorise a poem and recite it in private; it obviously is copyright infringement to build a machine that does that and grant public access to that machine. (Or does anyone think that's not obvious?)

Does that complex algorithm for the check digit have any advantage over the much simpler algorithm used for EANs or 13-digit ISBNs?

That's an interesting theory, but isn't it a different set of people consuming the audiovisual material? So, roughly speaking, in the past, an educated minority read The Times, while most of the population took no interest in politics and foreign affairs. Nowadays public opinion matters so various powers (often foreign powers not controlled by the local establishment) generate material designed to influence the general population, which isn't exactly literate, as you'll know if you've ever had to do jury service. Meanwhile, the educated minority continues to read The Economist or whatever (The Times is rubbish nowadays).