Why Hood received a roomier turret design

What benefit did Hood's revised turret design provide over earlier Royal Navy 15-inch mountings?

It was roomier and intended to make loading faster and operation easier for the crew.

The answer distinguishes Hood's main-battery mountings from the earlier Queen Elizabeth and Renown arrangements. More internal space was intended to make the machinery and ammunition-handling process easier for the gun crews to operate. Better working conditions could support faster loading and reduce the friction of serving a heavy gun in combat. The discussion also notes that triple turrets were considered at one stage, although the design did not proceed with them. Turret architecture is therefore presented as a human and mechanical system, not simply an armoured box holding guns.