If you're criticizing a three word slogan for not being a 5000 word policy white paper, then you're not discussing the issue in good faith. People say that government should "trim the fat" and are not dismissed as body-image absolutists who think every one of thousands of public employees should get invasive liposuction. People say that the government should "cut my taxes" without being dismissed because the government shouldn't individually adjust tax rates for just one person. Somehow, those three word slogans are always understood as a figure of speech standing in for a more detailed policy -- whether it's a good policy or not.
Generally, the police do any number of roles:
- Maintain the safe operation of the roads by ticketing unsafe vehicles and drivers
- Investigate crimes, find suspects and pass this information on to prosecutors
- Recover stolen property and record thefts for insurance purposes
- Interact with people on the margins of society and help them
- Resolve minor interpersonal disputes, like noise complaints
- Stop crimes in progress and arrest dangerous people
- Keep 'undesirable' people from locations where their presence or behaviour is 'undesirable'
- Hassle people who are not white
- Defend other police officers from external investigations or public pressure
It's probably not reasonable to expect one group of people to do all this stuff (and more). Some of it might not even be good for anybody to do (like the last few bullet points). It's impossible to train people to do every single task here equally well - even just the useful ones. A lot of police training and equipment focuses on high stakes violent confrontation, which on one hand makes sense, because it's so high stakes, but on the other hand doesn't, because it's only a very small part of the overall set of tasks. Many of the roles are unrelated to high-stakes violent confrontation, and some of them are even in opposition. Most of these jobs could be better done by people with training in social work, or forensics, or psychology or other specialized skills instead.
Imagine we had a large service of people whose job it was to go around to houses collecting recycling, compost and garbage, as well as to extinguish fires. It makes a lot of sense, because fires can start anywhere, so it's good to have people scattered about the city ready to fight fires at any time, lifting bins and firefighting are both heavy, physical jobs. Part of the mentality of extinguishing fires is that every part of the fire needs to be extinguished; you can't leave it anywhere to hide. That's very important, and it's drilled into the workers. So much so, that they sometimes think they see something behind a fence, and they pull out their axes and chop the fence down to get at the recycling. Sometimes, there's recycling there, and they congratulate themselves, and sometimes there isn't, but fighting fires is a high-stakes job and it's understandable if there are mistakes made in the heat of the moment.
Pretty soon, homeowners would start saying that maybe we shouldn't have these guys out there chopping fences down, and maybe the garbagefire department is causing more problems than it solves. That most of the work could be done by people who have no fire fighting training and drive trucks that don't need water cannons and ladders on them, and maybe a small number of people could be on standby with the dedicated equipment and training for the case when a fire does break out. Now, apartment dwellers who have none of these problems since their dumpsters aren't behind fences would say that it's ridiculous; you can't defund the garbagefire department. It's completely unrealistic to think a city like Calgary could function without a garbagefire department. What if a fire breaks out and the nearest people are only garbage haulers and a fire fighter has to be brought in from some distance? Extreme ideas like this only discredit a reform movement.