Not all police shootings are equal
The justified shooting of a black man in Philadelphia led to days of riots, looting and arson. And we have to take a step back from an absolutist position. Some people reflexively defend any police use of force, and others argue that any use of force (especially deadly force) is wrong and unjustifiable. That is much easier than doing the hard work of examining the facts of each individual case and coming to a conclusion. Absolutism is always more difficult than discernment and judgment.
Now, are there things that can be done to reduce the likelihood that deadly force will be needed? Sure, and it is reasonable to examine things like creating distance. But once someone is advancing on you with a knife, you have to make a decision to protect yourself and innocents around you. Whether the man has a history of mental health issues does not change the danger of a knife.
Some have said suspects should be shot in the leg, but experts will tell you that you always aim for center mass. Legs are a smaller target, and someone could keep advancing - especially if he is high on something. Life is not like the movies: There is no such thing as perfect accuracy with a handgun in the real world. Those of us without a law enforcement or military background often do not understand these things.
Yes, there have been many bad cases of police use of force. Yes, there are reforms that can be made, especially in not creating a situation where use of force is necessary. The reason the shooting of Breonna Taylor was so bad is that there never should have been a SWAT raid on her apartment to begin with. But policy changes are a separate issues from choices police officers have to make in seconds when confronted with imminent danger to themselves and others.
In the Philadelphia case, the officers made the right choice.