Why did Commonwealth countries not build more cruisers or larger warships?
Short answerThey lacked sustained investment in the interconnected industrial infrastructure needed to produce large warships.
NotesLarge warships require armour production, specialised foundries, heavy fabrication, assembly capacity, machinery suppliers, and transport links to converge. A dry dock or hull-building slip by itself is not enough. Governments first have to decide which capabilities they want to retain and then fund the connected system over time. Commonwealth cruiser construction depended on that whole production system, not on one missing factory or design.