Germany uses DD.MM.YY(YY). Dashes are for weirdos like me, and only for ISO dates, never DD-MM-YYYY.
And I assume this is the usual one in Europe in general for a human-readable context, like within a sentence. And as you said, dashes only in YYYY-MM-DD which is hopefully used always in any data context.
Where is that?
I would guess this is more like 'most people use /' and 'most people where I am use month first'; therefore those using - separation are weirdo Europeans/rest of world putting the day first.
The separators (especially with that order) are not.