There's so many issues as to why this is the case, but ultimately it all boils down to the fact that there is zero repercussions for bad cops. As others mentio

There's so many issues as to why this is the case, but ultimately it all boils down to the fact that there is zero repercussions for bad cops. As others mentioned, the police actively filter out smart cops from the ranks. They viciously pull rank around and protect bad cops, and oust any cops that threaten said bad cops. Then when they refuse to do their job, we reward them by paying them more. Giving them larger budgets. Giving them more toys to wave around. Like here in Austin the police are useless. You can report a crime with video evidence of the person and they do nothing. Look at Uvalde where they refused to even pretend to be the heroes they're portrayed as and the budget they have there is insane. It's exceedingly frustrating when every single encounter you've had with the police is outright negative and nothing is being done to fix it.