RSVP is from French.

I wish I could cleverly work in a "QED" here (from Latin) but it just doesn't fit.

I was talking about spoken language, not the existence of initialisms per se. Though I'd wager they are a lot more prevalent in written American English than in most other languages as well. Nobody else would think of inventing an initialism-euphemism for body odour (which I guess already is a euphemism for "smell" for example. Or "significant other".

By the way, QED is just a calque from Greek. (Like most things Roman...)

Funny, when I was born and grew up outside the US it was very common there too. Perhaps you'd like to scope your claim down to a specific group of people who find it annoying?

They are quite prevalent in Russian as well (though I am not sure if American English is actually “peppered” as you claim).

Stupid Americans and their checks notes acronyms.

Can you find a non-American that doesn't find it cringe to use "BM" for "poo"?

>Can you find a non-American that doesn't find it cringe to use "BM" for "poo"?

As an American, I'd find it hard (at least in my circles) to find an American who doesn't find it cringe worthy.

In fact, I don't think I've heard anyone use that term in at least forty years.