Community self-defense is absolutely necessary, and I'm not taking the position that acts like murder should be shrugged off. No amount of healthcare and housing and social programs will completely eradicate anti-social behavior, and at the end of the day we need to maintain public safety.
My point, which has been echoed by the various links that I've shared (and the article (which you're commenting on (which you should read!))), is that the vast majority of public safety problems don't need to be solved by the police. Quoting an article, because explaining this repeatedly is getting exhausting:
> Part of our misunderstanding about the nature of policing is we keep imagining that we can turn police into social workers. That we can make them nice, friendly community outreach workers. But police are violence workers. That's what distinguishes them from all other government functions. ... They have the legal capacity to use violence in situations where the average citizen would be arrested.
> So when we turn a problem over to the police to manage, there will be violence, because those are ultimately the tools that they are most equipped to utilize: handcuffs, threats, guns, arrests. That's what really is at the root of policing. So if we don't want violence, we should try to figure out how to not get the police involved.
People experiencing mental health crises don't need cops, they need social workers. Someone with a broken tail light doesn't need a cop, they need someone who can quickly and safely replace their tail light.
There are a small number of situations where public safety might require violence, but police officers are over-armed and under-qualified for the vast majority of calls they show up to. Last year the most common 911 call in my city was for an "unwanted person" [0], which I understand to mean 'experiencing homelessness', where cops really can't do anything to help. I'm optimistic that our communities would be better served by less-armed and more-qualified professionals who can use tools other than violence.
[0]: https://www.wweek.com/news/2019/02/06/portlanders-call-911-t...