Earlier quoted context omitted.
Firearms are deadly force. The decision to use them is the decision to use deadly force. People can disagree with the use of deadly force. If deadly force is allowed, it still makes sense to make its application as precise and limited in scope as possible. Hollow points, compared with full metal jacketed bullets, reduce penetration, reducing shoot-throughs and the potential of injuring those who are not the target. T…
Then why do the militaries still use ball-ammunition? Here's what I was told when I was in the service. The goal is to incapacitate the target, not to kill. From a military standpoint, incapacitation of targets causes additional burden to their sqaud-mates. It also demoralizes the enemy. Weapons are used for many things, not just deadly force. They act as intimidation (warning shot), deterrence (visual presence) as w…
Considerations like additional burden and demoralization are battle-field considerations: they're different from what police are typically involved in, where you want to remove an imminent or active threat to the public. (Just to reiterate, there are a lot of decisions that people can disagree about leading up to the decision to use deadly force in police work and whether that use was justified in any particular situation. That's not the discussion at hand here.)
Your examples of intimidation and deterrence are both indications that deadly force is available and willing to be applied. From the standpoint of brandishing, it doesn't matter what types of rounds are used. I'm not clear as to how often police actually fire warning shots, but if this is this case, they would be also be interested in ensuring the shot does not shoot through the intended target. (Shooting into the air is incredibly reckless and I can't imagine that's something police would be trained to do.)