Why shouldn't we decriminalize drugs? Clearly, treating drug use as a criminal justice issue rather than a social and public health issue has been an absolute failure- in large part because a person can't go to any governmental agency asking for help in dealing with addictions without risking arrest. There was never any reason to arrest people simply for using drugs: those using them are victims of various levels of pain and loneliness- it serves no purpose whatsoever to put people in jail or prisoin simply for using drugs; they aren't the victims, not the problem. And quite frankly, people don't just wake up one morning and decide to start using drugs just for the random hell of it-it's pretty much in reaction to some deep level of internal agony, or perhaps a sense of hopelessness.
If they arrest anybody, they should only arrest dealers and suppliers.
BTW "defunding the police" wouldn't leave us with no law enforcement mechanism at all...what it would mean is we create a new form of preserving public order that focuses on de-escalating situations, on addressing the root causes of crime, and, when needed, on actually showing up in black and brown neighborhoods when the people in those neighborhoods call the cops. Why SHOULDN'T we admit that the existing model of policing, especially that part of the model that holds that.
As to the UK, the reason it is in the red is that it has been badly underfunded by virtually every UK government since 1979-even "New Labour" didn't fully-fund it. A decent society can't treat healthcare as a commodity and a privilege.