Why treaty cruisers retained twin turrets

Why did more treaty cruisers not use triple turrets to save weight?

Turret maturity, damage tolerance, magazine layout, and differing design priorities often outweighed the theoretical weight saving.

Triple turrets were not equally mature or practical when every treaty cruiser was designed. Some navies preferred twin mounts because four turrets divided the battery into quarters, limiting the loss from one disabled mount to 25 percent instead of one third. Magazine balance and the intended role of the ship also shaped the choice. Triple turrets could still make sense, with twelve guns suggested as an attractive cruiser battery when the design could support it.