We do, almost exclusively.

We'll use Y/M/D for systems or ordering, sometimes.

I can't recall having ever seen Y/D/M used in any notable sense.

This is correct, the most common short-hand format in America is MM/DD/YYYY (possibly two digits in the last group). Dates like 05/28/2025 and 28/05/2025 are unambiguous enough to deal with order differences, dates like 06/03/2025 are not.

Year first and dashes is pretty much exclusively YYYY-MM-DD, no ambiguity; 2025-03-06 cannot be interpreted in any manner other than "the sixth day of the third month of the year 2025"

OP is probably little-endian.