Why large uncrewed submarines challenge the SSK case

How useful would diesel-electric attack submarines be to the Royal Navy or US Navy?

They could multiply numbers, but large uncrewed vehicles cover many of their roles while nuclear submarines better match existing global missions and support systems.

Large and extra-large uncrewed underwater vehicles can perform much of the local or persistent work used to justify a new SSK fleet. Removing people also eliminates much of the volume and power devoted to air, lighting, heating, food, sanitation, and habitability. For Britain and the United States, concentrating skilled crews and industrial support on nuclear submarines may yield more useful deployable capability than opening a second crewed-submarine pipeline.