I never quite got what the end goal is for people who paint the entire concept of police as a bad thing.

As with many things, it's their history and behavior.

Could a friendly police force that just wants to keep everyone safe such as you describe exist? Probably. Do they? Not in my experience.

If you have an interest to learn more on the topic, I suggest this podcast miniseries, listened to IN ORDER. (It's essentially one long discussion with references.) So at this link you'll need to start at the very bottom with the June 23, 2020 episode.

Give the hosts a little time to get to know each other, IMO it's a little bumpy at the start, but overall one of the most interesting, enlightening, and well-sourced and cited documentary podcasts I have ever listened to. It will require a few hours of your time, however.

https://www.iheart.com/podcast/1119-behind-the-police-63877803/