There's a strong argument to be made for police accountability and conduct. But this post seems to complete ignore the actions of demonstrators and the journalists (often self-proclaimed and self-employed) embedded within them. Look at the disparity between Portland and Minneapolis with respect to the rest of the country: New York has 20 times the population yet only half the journalist arrests. Portland has the same number of journalist arrests and New York but only 1/12th the population. These are order-of-magnitude differences, in cities that happened to have widespread rioting.

And from a more firsthand perspective, I can say that in my hometown of the Seattle metro I never had witnessed the same level of chaos. Armed demonstrators cordoned off a several blocks of the city and declared it off limits to police, and successfully did so for almost a month. Thus is something I have never witnessed before. Nor have I ever witnessed widespread looting outside of Seattle. I live in Bellevue and stores across the street from single family homes were being looted. I saw people walking out of Bellevue Square mall with stolen stuff in broad daylight as though it was completely normal. Neither of these were things I witnessed during the Michael Brown protests or other demonstrations against police conduct.

Both the data and my lived experiences indicate a correlation between more extreme behavior among protestors and more arrests. If we could point to demonstrable differences in the criteria police use for arrests you may have a point. But presently I see little reason to conclude that the disparity in arrests in 2020 are due to policing changes rather than the behavior of demonstrators.