You need to read the law to understand it better and also understand the current rulings that courts have provided on filming police. This law is none of those things that you state it's simply codifying a distance for what the courts have already upheld that police can do.

If you are party to the police interaction you can film closer than 8 ft. If you are in a car as a passenger you can film the interaction and the police cannot ask you to stop. If you are a non-party person simply watching the interaction the police can now ask you to maintain a distance of 8 ft.

Courts have already upheld routinely that police can ask people who are not party to the interaction to step away and they can create a reasonable area around them and the scene and keep people out of it. The definition of reasonable area varies based upon the situation. This that a reasonable area is a minimum of 8 ft. There are situations where that distance may be greater.

Regardless of what you think of the police they do need to be empowered to keep bystanders out of the middle of an interaction with their cameras in order to conduct their duties. 8 ft for a bystander is a very reasonable distance. At 8 ft your camera can see anything that a human-sized person is doing it to another human-sized person and it can record the audio of that interaction as well at 8 ft.

And as always the person who is party to the interaction can record the interaction and this is codified in this law as well. Laws like this do more to uphold a citizens ability to record the police then it does to take it away. Any reasonable person would understand that because without a law like this the police could argue that 50 ft is a reasonable distance. Now we have a law that says 8 ft is a reasonable distance in Arizona.