> that is not used anywhere in daily life
Does it matter? MM-DD-YYYY is used in America and makes DD-MM-YYYY ambiguous, but as far as I know nobody uses YYYY-DD-MM, so ISO8601 should be perfectly fine, especially if users are trained. Besides, if you're not used to it, starting with the year forces you to think, which is desirable if you want to avoid human error.
I couldn’t have named the standard and never read it before today, but I’ve used YYYY-MM-DD for naming my own folders & files for a couple of decades, for the simple reason that it sorts correctly in chronological order.