Few issues with the straightforward narrative you present.
Cops will slowly corral protestors as curfew draws near by setting up blockades or raising drawbridges. Peaceful protestors want to go home but can't. They're confused, and then curfew hits and police begin loading them into wagons. It's not as simple as get home by curfew.
Cops will infiltrate and instigate protests using a variety of tactics, the goal being to escalate tension, and justify the amount of force the cops wish to use.
Similar to your stated preference, they can't wait to be able to justify beating citizens with an overwhelming show of force. It's the fastest way back to status quo. A status quo you admit is broken, but worth using violence to return to. There's a catch-22 in your reasoning here you might be able to poke at.
Body cams and other forms of accountability do not work because the disciplinary board is not independent and not impartial.
Perhaps our countries aren't so different.
It was not broken to the degree that there is rampant arson, theft, violence and murder.
In fact, until it became politically incorrect to say it - the narrative amongst the media and civil society was that people should stay home and stay safe because of the coronavirus pandemic. That was the immediate status quo.
There had been protests by groups who wanted to reopen their businesses to feed their kids, but those protests were met with warnings and lectures about how it is dangerous to do so.
Shortly after, people went out in droves, with no regard for public health or safety or law and order and looted businesses as some perverse act of protest and this seems to be glossed over.
There has obviously been a problem with policing in your country for a long time, and body cams were an attempt to improve the status quo. In fact, body cam footage will be used as evidence the case of the officers who murdered George Floyd. The officers were charged in the average number of days that it takes to do so. They will face a jury, not a disciplinary board.