At a minimum, watch 100 videos. I did last night, only took about an hour, it's easy to find some to nitpick, some which are ambiguous ... and plenty that are totally horrifying.
If you can watch 100 videos in a row from Greg Doucette's list and say, "the militarization and use of force tactics of US law enforcement are not a problem" then I'd like to hear why you think so given this evidence.
Otherwise you're not speaking from an honest grappling with what these videos contain.
The police are uniquely powerful against normal citizens. Not only are these videos clearly representative of a large number of abuses, but their colleagues rarely try to stop those abuses. Few of them will be held accountable. The police are almost always above the law, if not outright immune.
In "cop vs. citizen" when it's just words, cops will always win. Even when there is video, it is difficult to get justice. A cop unjustly hitting someone and a citizen unjustly hitting someone are two different crimes, in my opinion, and the cop committed the far worse of the two.
The fact that everyone watching George Floyd get murdered in slow motion was too scared to tackle that cop is proof enough of the power to kill with impunity that cops have.
You lost that bet.