Why the U.S. Navy cannot shrink an escort much below a frigate

Should the U.S. Navy build an ASW trade-protection ship smaller than the Constellation-class frigate?

Probably not, because U.S. escorts must cross oceans and still arrive with enough endurance and capability to operate effectively.

A smaller escort is not automatically useful to a globally deployed navy. U.S. forces begin an ocean away from many likely operating areas in both the Atlantic and Pacific. A ship much smaller than the Constellation-class frigate risks losing the range, endurance, and capability needed after that transit. The design problem is to deliver an effective ASW escort to a distant theatre, not merely fit the equipment into the smallest possible hull.