A lot of this will happen without unions anyway. It seems like every country has a completely different cultural gestalt surrounding police work.
For some reason, modern police culture in american seems to increasingly value a corporatist perspective of us vs them (them being everyone who is not police), the normalization of violent response, fixation with the concept of face and widespread corruption.
Police Unions didn't create them, and abolishing them won't eliminate their lobbying power, you don't need a union to organize yourself around a lobby.
Let's not use this excuse to perpetuate the demonization of unions. After decades of increase concentration of productivity gains in the hands of capital at the expense of labor, and as we enter the AI age, this is the least thing we need.