You could counter multipayload missiles by hitting the missile earlier in its trajectory before the payloads deploy, that was the plan for MIRV nukes but it requires usually forward interceptors or perhaps energy weapons we don't yet have.

Hm, Iran destroyed several of the radars used for seeing their missiles in the early stages of their trajectory.

Hitting Ballistic missiles "Midcourse" as you suggest requires interceptors that look more like https://en.wikipedia.org/wiki/Ground-Based_Interceptor or https://en.wikipedia.org/wiki/Arrow_3

It is.... Entirely infeasible to deploy these against tactical ballistics like Iran is using.