I'm of a mind there should be more union protections for everyone, not fewer. The strong protections that police have should be the norm.
As for police reform, I moved from the US to a Nordic country known for professional and committed cops. Mind blowing, how calm and peaceful and unfraught dealing with cops are, here. When I first moved here, it was the police department that handled immigration matters and I nearly had a panic attack. Completely unnecessary fear.
To be a cop here requires 4 years of training, a degree, as well as ongoing psych evals. Everyone including the police are just so freaking reasonable it can be disconcerting!
I'm not sure what is going on in the US that makes the government so extractive. That corruption is the root cause of any police corruption. But more training and exclusivity couldn't hurt.