I agree that the European format is probably not more useful, and you probably convinced me to go change my settings to YYYY-MM-DD. But I _do_ think that the European format makes more _sense_, it being in chronological "magnitude" order.
I can understand that perspective, although I maintain the usage is only preferred because of familiarity.
Since you are already on the fence with ISO8601 I invite you to consider time of day. Would you use second:minute:hour? That is also in (reverse!) “chronological magnitude” order.
Putting the day first isn’t actually a benefit because you still need the year and month for context.
Any favoritism of the EU format is the same as the US format. Just familiarity.
ISO8601 is the only way.