If you compare the standards to let’s say: Switzerland (2 years in the academy, the candidate must graduate with a diploma in policing. The first year is theoretical: mainly in the classroom learning about law, tactics and de-escalation. The second year is spent on the job in practical field training with a respective police force).
While police training in the US varies on state: but it’ll last up to 16-21 weeks (it’s pretty bad) before they’re sent on the streets, no wonder why you hear about cops resorting to violence first rather than a de-escalation. There’s an example from Norway where cops didn’t point their guns at a drunk guy, instead they laughed with him.
Both Norway & Switzerland DO NOT have qualified immunity for officers, meaning they are subjected to the same laws as every other citizen. But apparently the USA likes to consider cops above the law via qualified immunity (which is a reason why you barely hear an American cop being held accountable for their actions).
The responses are different: since US cops are like “GET DOWN!” or “DROP YOUR WEAPONS!” while Norwegian cops are like “Please, stop doing that” being said in a more pacifist tone that doesn’t evoke hostility (that’s an issue you hear from American cops, as they shoot first rather than trying to talk their way out).
I think you are starting off with an incorrect premise: In the US, the role of the cops is not to keep people, or society safe. It often also has very little to due with “the law”.
The role is to keep the rich and powerful, rich and powerful. They are meant to oppress people, and keep the slave-machine running. Cops shooting people, stealing from them, escalating situations, and not knowing the law is the intended situation.
In that sense, the cops are doing their job to great effect, and don’t need any more training.