Since I'm apparently feeling my etymological thinking tonight, I'll go ahead and drop this concept on you:
Acronyms weren't in common use before the 1900s. Like the first reference to the concept in German is from 1921 and in English was 1940.
That's how complicated the world got -- we had to start abbreviating shit into pronounceable shit so we could still verbally chatter about complicated shit in verbal one-word shorthand.
And now we routinely mash old acronyms into new acronyms at times.
@sydneyfalk https://en.m.wikipedia.org/wiki/List_of_medieval_abbreviations
Admittedly it needs citations, but I could probably find some.
* "Common use" was the bar, which is by definition not exactly well-defined. I'm aware of the existence of acronyms in places throughout the period previous to the years indicated -- but they were not what I would call "in common use" during those times.
And to address another item in David's response:
* Abbreviations aren't acronyms. Acronyms are a subset of abbreviations that are pronounceable or intended to be so.
SydneyEFalk
David de Groot 𓆉
Angostura