I mean a "real" national meet would have to have the bill footed by something like the likes of USATF. Which they're not even flying our top pros for USAs/Trials out to compete each year. So I don't expect they're gonna start doing it for high schoolers.
I know a lot of people give the shoe brands crap, but the shoe brands are footing the bill for the closest thing that we have to your wish list of a national high school meet. Yeah there's a bunch, but the best of thes best kids know who's competing where each year and the talent follows each other to the same meets (which is why everyone would rather compete at NBON and it's more honorable to get 5th or 6th at that meet vs getting 1st place at an easier meet like the Adidas meet)
Some brands do foot the bill to bring kids out, I appreciate when they do so it evens the playing field
The closet thing we have I suppose is teens vying for the U20 spots at world meets. Which I'm fine with - it's high schoolers. I see all of the great, fast, record setting racing options that they get from these brands, and "wow, they need yet another racing opportunity" has yet to cross my mind