We shouldn't need this many police officers because most things they prosecute people for shouldn't be crimes in the first place. Stealing food and water shouldn't be necessary to survive, for example.

Occasionally there would be a rare ill-adjusted person who wants to hurt other people just for the sake of it. You don't need the current volume of the police force to deal with those. More than that, under the current system those people end up controlling the police.

Abolishing the police right now in its entirety would be premature. We should start by abolishing capitalism and directing the police to apprehend the actual criminals (by which I mean the billionaires).