These are humans too and they're watching society (and especially media) totally dehumanize them. To some degree their anger is arguably justified.
I feel like it's impossible to get an accurate feel for how many people are protesting and what proportion of the population supports the protests. But I have a feeling it's a minority, maybe 10-30% of the population, in which case you cannot let a fraction of your population hold your entire city hostage, especially when opportunists are simultaneously looting and burning, though that seems to have calmed down recently.
Point being, if the protestors won't listen when asked to leave, and if they are disrupting the lives and livelihoods of 70-90% of the population, I don't see any option other than gradual escalation, which typically precedes gas and rubber bullets.
The police in a city in Canada went on strike in the late 1960s[1]. Things didn't go well. And we've already seen that American demographics are willing to burn and loot even with police present...so I don't mean to defend police but I really don't see anything good coming from police standing down or refusing to use force.
1.https://en.m.wikipedia.org/wiki/Murray-Hill_riot
Edit: Downvotes are intended for discouraging low effort or otherwise poor comments, not to shame people for disagreeing. Whether you like it or not at least half the country supports police, they play an important role in society, and that makes this a discussion worth having.