Why 9.2-inch guns had a useful rate-of-fire niche

Why was the 9.2-inch gun seen as a useful calibre?

It offered a larger shell than an 8-inch gun while retaining a much faster practical rate of fire than 10-inch and heavier weapons.

A practical threshold in projectile handling and loading machinery. A 9.2-inch weapon can still approach the rate of fire associated with an 8-inch cruiser gun, quoted here as roughly six to eight rounds per minute under favourable conditions. Moving to 10 inches imposes much of the slower loading burden found in low-end battleship calibres, closer to two or three rounds per minute. The modest increase in shell size therefore may not justify losing roughly half the volume of fire.