Build premium ships before the war and austere ships during it

Why do destroyer escorts and escort carriers get looked down on despite distinguished service?

Premium ships justify peacetime spending, while austere ships are exactly what navies can build quickly once war starts.

Premium ships are necessary because they take so long to build that a navy will probably fight with the major units it already has. Smaller and cheaper ships follow a different logic. They can be built quickly and made survivable enough for specific wartime tasks. Fleet planning therefore has a place for both high-end prewar units and austere ships produced in greater numbers after war begins.