I can speak about europe, but I don't think that that the US started on a serious downward trend until nationalism started rising.
But let's say that the US was really on a downward trend -- it's still a big logical leap to say that it's because of some sort of lack of nationalism, especially because whatever downward trend there was has been sped up a lot with the rise of nationalism.
Nationalism of the sort we're seeing now is correlated with the collapse of nations, not with healthy ones.
And I trust any random person off the street far more than I trust Musk. I spend a great deal of effort trying to keep my data out of the hands of Musk and his crowd out of a sense of self-preservation.
This is handing very sensitive personal data to a group who has made it clear that they are my (as well as most of the people in the nation) enemy and want the worst for us.
So far, Trump has easily been the most pro-crime president in my lifetime. I weep for my country and the horrible years these people are bringing to us.
Although I agree, a culture that allows companies like Palantir to be successful has indeed lost its way.