New precedent trumps old precedent. It's why Brown v Board is the law of the land and Plessy v Ferguson isn't. There (to my knowledge) hasn't been a challenge to the NFA that's reached the Supreme Court since that Caetano case in 2016 and the court hasn't explicitly struck down the prior precedent of its legality, so it still stands based on the other points in the ruling. Even the current NFA-related cases against bump stock and pistol brace bans working through courts are based more on whether the ATF can consider them as NFA items rather than whether the NFA itself can be considered constitutional, so it's likely to stick around.
You had me up until "fund the police state" as if US police unions aren't already the most powerful groups in the country to be a member of, as if any state or municipality has meaningfully cracked down on policing abuses, as if the US doesn't already have incarceration rates 5x the next NATO member, as if the US doesn't already spend more on policing than all but 2 nations do on their militaries, as if police spending ever dropped even 1%, and as if supposed funding cuts aren't just city council members shuffling the numbers around while the departments themselves see steady budget growth year-over-year.
Your experience is simply finding yourself calling in an incident on the wrong street for the wrong person, a call the officers know won't affect their bottom line. It's always been the case, whether passively delaying responses or actively corralling rioters away from wealthy districts. It's not because they're suffering for funding, it's because they know they can get away with it.