It’s possible it’s a bit of an “arms” race, the police are more aggro but so are the public. At least in public perception back before the 70s its was perceived that by and large there was “respect for authority” but that’s eroded over the decades for various reasons among them court cases asserting more rights for individuals where cops can’t just up and arrest willy nilly. But also movements like “sovereign citizen” leaks in places enough to affect behavior elsewhere.

Also weapons are relatively cheaper today than decades ago.

There's an insane number of police shootings where it turns out the person was looking at an insanely large sentence and they "weren't going back to jail." From that perspective it's not even clear they're acting irrationally -- if the penalty for third-striking for stealing a TV and murder is the same then some criminals are going to make it worth their while.