It depends on what type of catastrophe a giant lava flow would just burn to a crisp organic remains. A flood might bring in more organisms that would decompose bodies faster. There are several type of those environments around today and presumably several also in the distant past. For example if you want to make sure you get fossilized you could throw yourself into a peat bog or into the Dead Sea.
You are correct. This is nothing new. In fact, you can say that throughout history this is the norm. Society have generally been elites hoarding true information while spreading falsehood onto people for them to be servile. In fact, the recent trend of middle class and generally high level of knowledge for the masses is quite abnormal. America is simply on the path of regression to the norm. And we'll be back in the good old days of nobles and peasants soon enough. But you are correct though that America will live on. So will its people. The only difference is quality of life. A few will be even richer. A lot will be a lot poorer. Well, that's life.
