My question is, why call it "defund the police"? The core of the idea is that, in many cases we can change our response from involving police officers to involving some other group who will hopefully be able to do a better job. The fact that this can be accomplished by reallocating funds from the police department, to avoid needing to levy taxes to raise revenue, seems like almost the least important part of the plan. Even then, "defund the police" is only the first half of "defund the police and use the additional funding to create another group that picks up some of the police's responsibilities".
My feeling is that many people view police with antipathy, so they like the slogan and concept of "defund the police" because it feels like a retaliation against the police. I strongly suspect that other ideas, some of which may be much more beneficial than changing the response, will be ignored if they can't be phrased as a tactical strike in the culture war.
Here's one list of proposals [0] for police reform, many of which seem very promising for how little cultural sway they have (delegalize police unions, abolish QI, decriminalize victimless offenses, etc.) I wonder if they have so little sway because they can't be phrased in a sufficiently incendiary manner.
(And by the way, just because there's antipathy towards the police doesn't mean the police are directly at fault. For instance, if police are made to enforce unpopular legislation like the war on drugs, that will obviously make people dislike them but the root problem is somewhat upstream)
[0]: https://medium.com/@yudkowsky/a-comprehensive-reboot-of-law-...