The public notion of good policing and the actual practices police departments follow have been diverging for several decades (if they ever converged). What we're seeing right now is not some inexplicable increase in bad behavior or cops deliberately targeting journalists. For modern American police this is just business as usual, except the volume of deployment is significantly higher than in the past few decades and the visibility is much higher as well.
Edit:
There is a flip side to this coin. When you have a systemic problem of this scale, you should be cautious about making simplistic (especially moral) judgements about individuals in the system. When someone's training, incentives, position in the community and even equipment nudge them towards bad actions, even decent people will routinely do bad things.
Interaction with police is one of the rare cases where self defence doesn't cut it. In fact, defending yourself just gives more justification for law enforcement to apply more violence.
Imagine if you were George Floyd, and you knew you were going to get killed. What do you do? If you don't resist you die. If you do resist you might still die or at least be assaulted, then charged with resisting arrest and will have "deserved" the violence by resisting at the end of it.
On the bystander side too. Everyone watching knew it was wrong, but there is no good way to intervene. You either put yourself in harms way, and probably won't effect the outcome, or intervening action will be used to justify whatever violence was used, or likely both.