Why hypersonic missiles do not replace nuclear deterrence

Could hypersonic missiles replace nuclear weapons as a stabilizing deterrent?

No; they may contribute to stability, but they operate at a different scale and cannot replace the nuclear deterrent's function.

Almost any weapon can contribute to stability when used within an appropriate strategy. Hypersonic missiles still cannot replace nuclear weapons because the two generate effects on fundamentally different scales. A fast, difficult-to-defend delivery system serves a different political and destructive function from a nuclear deterrent. Speed alone does not make the weapons strategically interchangeable.