Why capital ships still need guns before torpedoes

Is there a case for heavily torpedo-armed capital ships?

Not as a substitute for guns: torpedoes are mainly for finishing an enemy, while guns offer more dependable long-range damage.

Guns deliver more predictable damage at longer range and therefore remain the dependable primary armament. Torpedoes are valuable for finishing a damaged opponent, but they do not offer the same probability of damage at the opening of a capital-ship action. Achieving a reliable early torpedo hit would demand a very fast, high-risk destroyer-style approach. A heavily torpedo-armed capital ship would trade dependable gun power for a weapon whose effective use depended on dangerous closing conditions.