While I agree that people in social media users have biases and ignore even a reputable evidence, but with economics though, it’s complicated. One economic metric alone is sometimes not enough, has limitations and therefore doesn’t give the full picture. I don’t know much about purchasing power parity to comment on it, but the best example I can give is on GDP or gross domestic product. A country that has high GDP in let’s say, $100 billion, shows that the country is rich. That implies that the population in that country are also also wealthy enough, right? Not really. If the GDP per capita/person is in $1,000 in that country, as opposed to US’s of over $60,000, then the people in that country are not affluent enough.
Immense wealth is nothing if they’re not distributed equitably. The higher purchasing power of Americans is taken on average but does not take into account that certain areas do not have higher purchasing power. California would have higher purchasing power as opposed to rural folks in the Rust Belt. And the latter are Trump supporters for a reason.