Some clown posted that the experimental missiles were all falling apart.
He’s not totally wrong, other countries did have structural issues with their hypersonic prototypes. However, I can’t think of any in the last 15-20 years off the top of my head.
The other thing is that Sprint and Spartan were *big* missiles and were never going to be vehicle or air launchable. They didn’t have to be for their roles, but their size was indicative of the tech of the day.