>

This isn't really that unpopular. There are at least 3 countries that use this format.
31DEC2022. Leaves no confusion lol >

Is that the model number of some kind of appliance? >

It's the way they write the date in the US Military. >

Don’t know about the military but in the aerospace industry, this is how we put the dates in front of our signatures, when signing drawings and documents >

r/iso8601 >

I will always be a proponent of month/day/year because if someone asks my birthday, that’s how I would say it. 
I wouldn’t say “18th of April, 1983.”
I wouldn’t say “1985, December 3rd.”
I’d say “September 6th, 1989.”
(None of those are actually my birthday) >

Year should go last because it changes the least often. >

Day/month/year makes the most sense in my mind. >

100# agree once. Multiple Decembers are involved it's obvious >

This is for file names and sorting only for me. For most other stuff I use DD/MM/YY(YY). The most relevant parts should come first. For most of my notes I jzst leave out the year completely, because they are in a book / folder with the year.