Why a diving bomb struggled to replace the torpedo

Were bombs designed to dive beneath ships ever practical anti-ship weapons?

Ideas such as Highball existed, but controlling depth and effect made torpedoes the more practical solution.

A Barnes Wallis bouncing-bomb variant provides the closest real analogue to a bomb intended to reach a ship below the waterline. The concept depended on entering the water at the right point and continuing toward the hull. Depth control and fuzing made that difficult: a weapon that dived too far would lose much of the desired effect. Torpedoes solved the underwater-delivery problem more directly, which explains why the more spectacular bomb idea remained less practical.