On: Plain text is still one of the best technologies we have

[Analemma_]

If you write files in ASCII you’re already writing in UTF-8.

[sillysaurusx → Analemma_]

That’s true, though if you’re writing UTF-8 you have to handle the corner cases when reading UTF-8, of which there are many.

Fortunately they’re easy to test for and most languages have standard libraries that make this painless.

[bell-cot → Analemma_]

ASCII has, in principal, infinitely many superset.

And in practice, still a rather large number of them, going back to the 1970's - https://en.wikipedia.org/wiki/Extended_ASCII