Why the 20,000-ton 9.2-inch cruiser lost out

What happened to the proposed 20,000-ton cruiser with quadruple 9.2-inch guns?

It became too close to a battlecruiser in size and competed for the same shipyards as carriers and battleships, so the proposal lost its practical advantage.

The 1938 study approached Alaska-like size and capability, but its scale undermined the cruiser case. A yard able to build a 20,000-ton cruiser could usually build an aircraft carrier or battleship instead, creating a much harder procurement comparison. Smaller cruisers retained the advantage of using yards that could not accommodate capital ships. The counterargument was fleet numbers: a lightly protected 9.2-inch cruiser could yield more hulls for the same resources than a true fast battleship at a time when the Royal Navy was acutely short of cruisers.