Speed is irrelevant. It you can track a missile and project where it will be in it’s flight path you can send a missile to intercept it. An SM-6 missile has successfully intercepted ballistic missiles in tests.
BS!!! You don’t understand hypersonics. If the target missile is going much faster than the interceptor you will not be able to maintain a track on it. The Russians have also vastly changed their SLBMs/ICBMs by integrating with Avangard hypersonic sleds which makes them Mach 20-27 cruise missiles which change the axis and methods of attack. BTW an SM-6 is useless against low flying hypersonic cruise missiles. I know what AEGIS limitations are and it needs to be modernized.