I understand you distrusting the data, the biggest misgiving I have about it all is the testing dropping off at the same time as new cases (Ca being a big exception). That said however for the time being all the numbers are in agreement. If we look at the longer trend where logically we would see less cases -> less hospitalized -> less death the numbers are all in agreement with the ongoing trend.

I won't say that lying or misrepresenting all the numbers is beyond anyone but doing so in a believable way becomes difficult and is generally not that hard to spot.

If we consider that however and look at the recent drop at face value there is no real explanation. We could argue that what we saw in Fl and Az scared people into taking things more seriously but the effect seems much larger then just that.

I personally think there is something fundamental about the way this virus spreads through population that we have failed to properly identify at this point, which is just a more intelligent of saying I don't know. Even if we considering theories like lower herd immunity threshold the very localized nature of the outbreaks we have seen makes it hard to apply at any scale lower then countries/states.