I don't think anyone noticed themselves, nor has anyone listened when I've mentioned it previously, so I'll repeat:
Sometime decades ago, the police just stopped policing.
I don't have all the details. We can infer and speculate a bit that it didn't happen at the same time everywhere, all at once. But it can't have been much later than the 1980s or early 1990s, or I would have noticed.
The only thing that the police do with any earnestness or initiative are drug busts, and this is plainly because when they do drug busts they get to keep the proceeds whether that is cash or fast cars (that get new squad car paint jobs). They do the other things (local) politicians want, which is some ticket quota revenue collection once in awhile. They continue to begrudgingly take stolen car reports, because if more than a few voters complained they weren't doing that, eventually some politician somewhere would lose an election or be forced from office.
But there are no repercussions for refraining from any other sort of police work. Those scenes in The Wire where they're trying to convince rape victims not to report it (in that scenario, so their stats would look better)... not just narrative device. When we hear about them not going after a school shooter killing kids in classrooms, and we're straining our brains to explain it and the only thing that comes to mind is cowardice? Well, I've got a simpler, though no less bizarre explanation... it just wasn't in their job description.
This isn't accidental or temporary or bad management. You have Police Chiefs going on Twitter and chastising the public for believing that they should be able to park cars and not have their windows smashed and contents stolen. It is a matter of policy that they no longer do policing. This is backed up by case law that makes it official that they have no duty to the public to protect them from any crime.
Most of all though, you have a public that is somehow willfully ignorant of it, thinks that maybe they're just doing a bad job but doing the job, and if they're patient new people will be hired and maybe they'll start doing it moderately well again. It's baffling.