Yes, and no. People will act as they please if they belive there will be no consequence to said action, or if the result is enough to justify the consequence that follows. A man who kills his wife for cheating on him did so because he found that the result would out weight the consequence. A looter will only loot if he knows that there will be no repercussions for his actions.
If the police were dissolved instantly there would be mass panic, and societal destabilization. People look to the police for order and stability. The only ones who stand to profit from chaos and lawlessness are those large enough to protect themselves and their assets. You and I the private citizen will be swept away, killed, by large corporations in an attempt to limit loss due to looting, or the cartels that would form to take advantage of the now lawless society.
Who stands to gain the most from the continuation of cannabis prohibition? Not the police because, while they do get a small cut, majority of the profits go to private prisons and the cartels the run the supply. I am also under the impression that the heads of the prisons and cartels are secretly rubbing shoulders to keep their game alive.
The police are still necessary. However they are becoming more and more outdated a we continue to move towards a better, more peaceful society. But before they can be phased out we need to adress the problems that they answer. Domestic violence, theft, and mental illness are not going to dissappear just because the police do. These things would become more common and harder to deal with if the police were to dissappear over night.
To phase them out we need to promote public self defense education, end poverty, and become, as a society, more aware of the signs of mental illness. These things are not going to happen over night. It will take time on a generational scale to resolve. But if these things, and I am sure a few other things were to take place police as we know them would be a thing of the past.