It’s how the dates are typically said, here. November 6th, 2020 = 11/6/2020. [Edit: I had written 9 instead of 11 for November.] (We basically never say the sixth of November. It sounds positively ancient.) It’s easy to use, but I agree that YYYY-MM-DD is vastly superior for organization.
I’ve never once been confused about a written date whilst in the US. Your country’s other-side-of-the-Earth flip-floppery on how it uses dates really doesn’t (and shouldn’t) impact our system, which we continue to use because it has proven effective and easy. Trying to stagnate an evolving culture/language is pointless and about as futile as trying to force a river to run backwards. If people start jumbling up how we do it here, like you say Australia does, then that will be right, too.