Huh? I use yyyy-mm-dd quite frequently, for file numbering and things like that. But I live in a country where dd-mm-yyyy is very common. yyyy-mm-dd would be more consequent, sure. But still I am glad people here use that and not the much worse mm-dd-yyyy. Nothing more did I say. But it's ok if you try to put more in my mouth, just go on.
No need to make this personal. Think you are getting caught up on the personal vs general sense of "you". Could very well have said "why would one use"
In any case, I don't believe you nor anyone else has made a strong, consistent argument for why the US format is "much worse" than the European.
Why do you assume the year is the most significant digit? In general daily usage, it's often irrelevant.
It's a specific phrase used in mathematics that most people learn in elementary school.
It means "bigger numbers", because obviously the larger values are going be most important in determining range or scope. Would disagree on irrelevance since it's actually embedded into context.
As a previous user has already stated, the globe generally uses one of the two main conventions - dd-mm-yyyy or yyyy-mm-dd these are both common and very easily understood regardless of which way around they are. Only the North Amercian's do their own thing with their easily confused oddball mm-dd-yyyy format. Although this is mainly used domestically, in international dealings they tend use one of the two main "global" formats or simply use words instead of digits.
"Because we use it" is not a strong justification for why it should be used.
When it comes right down to it, the European date/time format is an illogical, inconsistent format. It's funny because the only defense I see of that is double down the same logic Americans use to justify their format.
You'll probably find your preference is mainly due to the orientation in which you read your own language. left to right (large parts of Europe/West) vs right to left (large parts of Asia)
That's the thing. Pointed this out over and over, but the European date format is not consistent with the way you write numbers in general or even with how you write time.
Look at Asia, where they write left to right, right to left and top to bottom. Regardless of orientation, dates will still be written from most significant digit to least which is in alignment with how numbers are written in general.
ISO 8601 is for data consistency, and is great for what it does.
However, the European format addresses the needs of the ordinary mortal, and has done so since the days when "science" was a just hobby for rich noblemen with time on their hands. (time on their hands..... geddit?
ISO 8601 works well enough for people in east Asia. Perfectly normal to say "2019年3月11日".
It addresses the needs of the ordinary person exactly because it stresses the "most significant" digit first. i.e. the day.
When you get down to it, this is the logic that Americans use to justify the US system. Colloquially, you're used to it.
I could be speaking to a friend: "Let's do this again next Sunday"
Me:"Yep, Sunday the 17th"
Him;"I'll just check my diary; we are still in March aren't we?"
Me; "Yep, so we'll go for Sunday 17th of March"
Him: "So, it's a date then; we'll do this again on Sunday 17th March, 2019 or 17-03-2019"
Me: "You bring your ex-wife, I'll bring my girlfriend, and we can swap over at half-time"
Not really making a point here. You could directly translate that into Japanese and each successive round you'll end up with ISO 8601. In the context of your dialog, it's really just an arbitrary transcription. Things that are prepended and be dropped just as easily as appended.
To look at it another way, some languages to pre-fix or post-fix adjectives. Based your example, you would probably make the case for why English should switch to post-fix adjectives just because it's easier for you to drop what comes after.