Cluster munitions are great against infantry in open field; less so against population centres equipped with advance warning systems. As it stands, they fail to even cause the damage worth offsetting by firing interceptors. The damage these inflict on Israel is not unsustainable, and they don't do much to create deterrence.

Given a choice of conventional 500-800 kg warhead or cluster munitions warhead, I think that the nations in the current conflict would prefer being on the receiving end of cluster munitions (as a less bad option) every time.

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.