I agree. I don't often see mini bags IRL. And, when I do see them, for the most part they're on teen / early 20's women. I'm guessing it's because this age group may not have the need to carry family / child things as much as older women???
I think many petite and / or younger women will continue to enjoy mini bags because they are functional for their particular silhouettes and lifestyles...Just like moms with mini vans of kids are still carrying huge bags that have "gone out of style" because they need to haul a bunch of stuff.
That being said, I think those who wear them just to be fashionable / trendy will switch to the "next big thing" when it appears.
And, I think the majority of us who've dabbled in mini bags as a curiosity, quickly grew weary of the incoveninece of not having our "stuff" with us. So, while we'll keep small-ish crossbodies in our arsenal for hands free / busy times, those truly teeny bags will never appear in our closets ever again.