I think that the timescale on which humans live matters here. The year field doesn't change often, so for the everyday usecase it's kind of redundant – it's probably the current year, so specifying it first is kind of noisy[1]. But on the scale of hours, it's the minutes that are noise, because you likely care more about the hour. So I guess the most ergonomic ordering depends on the usecase.

[1] This could be different if you're, say, browsing an archive. Still, if I'm looking at a thread from 2005, that context is in my head, and I don't need to be constantly reminded of that by seeing 2005-XX-YY.

In English, at least, it used to be that a document such as a letter would begin with a date indicating when it was written, and then for dates ±1 month from that date would express relatively, like so:

* "The 10th instant" / "10th inst." = tenth day of current month indicated in date of document

* "The 10th ultimo" / "10th ult." = tenth day of month preceding the one indicated in date of document

* "The 10th proximo" / "10th prox." = tenth day of month following the one indicated in date of document