Police aren't legally accountable for their actions so long as they're acting in the performance of their duties, and lots of departments knowingly have illegal policies on the books to maintain that immunity for their officers.

People try to sue over it, but the cases are thrown out by the local judge because there's no standing to sue unless the illegal policy had impacted you, so a cop basically has to kill someone before the policies are modified in the smallest way possible, but the killer cop still gets off.

Additionally, police are allowed to lie in most of their interactions with the public. They have created a culture that encourages dishonesty, so perjury isn't an ethical problem in their eyes.

The prisons are for profit and the state gets to keep anything it seizes.

Ignoring problems tends to make them rot faster. Hollywood is superficial, it's all we got. None of the basics are taken care of, it's why I left (e.g. wealth before health). No safety nets, desperation is easy to find. Limited opportunities if you can't afford to do anything. It's an unsustainable way to live, if you call that living. It's more like surviving.

ACAB includes European cops, by the way. Just because they're especially bad in the USA doesn't mean yours aren't also trash.

Not sure which country you're in, but how have your cops been handling environmental or climate protests? or protests in support of Palestinians?

It's an issue in many other countries as well and there are a great many contributing factors.

1. Race and "Tough on Crime" politics - Ever since the emancipation of slaves on the basis of race, there have been political figures passing discriminatory policy that allows police to pursue and harass people at their own discretion: black laws, Jim Crow era laws, forced segregation, the 1994 Crime Bill, etc.

“We have to strengthen our laws when it comes to mob violence, to make sure individuals are unequivocally dissuaded from committing violence when they’re in large groups,” Florida state Rep. Juan Fernandez-Barquin, a Republican, said during a hearing for an anti-riot bill that was enacted in April.

It's clear that you can convince people to deregulate and militarize the police if you convince those people they have a greater enemy. You can see these stances and policy directions mirrored across Europe as refugees and immigration from poorer countries have increased in the last decade.

2. Lack of Centralization - The FBI is in charge of investigating police departments, and sometimes you see jurisdiction overlaps which allows other agencies like the DEA, State Marshals, Sheriff's Department, etc to investigate each other, but in general a Police Department is held to no standard but their own until things have already escalated past a point of return.

Some federal programs have tried rewarding PDs that behave well and adhere to specific training or standards, but it's far from enforced.