Rifles are capable of much higher velocities with similar cartridges and add Temporary cavitation for additional lethality.
There is a significant body of evidence that Hydrostatic shock (more precisely known as the ballistic pressure wave) can contribute to handgun bullet effectiveness.
[6][7] These scientists observed neural damage in the brain caused by the distant effects of the ballistic pressure wave originating in the thigh.
A high-frequency oscillating pressure wave with large amplitude and short duration was found in the brain after the extremity impact of a high-energy missile ..." Wang et al. observed significant damage in both the hypothalamus and hippocampus regions of the brain due to remote effects of the ballistic pressure wave.
It is generally agreed that most intermediate handgun calibers will yield similar terminal results if using modern, quality ammunition.
Caliber selection often can be reduced to balancing a handgun's physical features; weapon size, magazine or cylinder capacity, recoil, and ease of use.
Since a central nervous system hit is very difficult in a dynamic situation, some people will use expanding ammunition or larger calibers.