Why did Germany make so little effective use of its destroyers after its early wartime operations?
Short answerIt lacked the critical mass because destroyer construction never received enough investment.
NotesIndividual destroyers can raid, escort, and screen, but those roles consume ships rapidly across multiple theaters. Germany simply did not build enough of them. Losses and maintenance therefore left the navy without the numbers needed for regular concentrated operations. The problem was force structure rather than a failure of one ship design.