Kinetic energy at these and higher velocities is a stone cold b*tch. Once a mach-15 projectile hits something solid, it basically converts to energy. Depending on design, it can be an all devouring lance of plasma.
Even at slower speeds, KE can get you amazing bunker busting. Look at the GBU-28 for a very old example of how that works: https://en.wikipedia.org/wiki/GBU-28
So this hyper thing flies low and slow? Then it climbs to the top of the high dive, also slow. But it locates a target and falls really fast? But no one is going to notice it climbing out? Yup, I can see why that would work every time. No one would ever take a shot at a dumb bomb flying straight up? Even our old F-14’s could catch that thing?
Simply swarm the incoming path of the hyper with several thousand drones carrying either explosives or steel bearings, and detonate when needed. Or send out two swarms, one that triggers impact before the second, which the second can precisely compute speed and direction of the arrival of the hyper and take out down.