On the last par: suppose that it is true that a) 10 years ago people were less self-centered, impatient or poor than they are now and b) 10 years ago there were more parties.
Does this form the basis of a well-evidenced claim that there are fewer parties because of increased poverty, narcissism or impatience? Of course not, because there are lots of other time periods we can easily look at.
For example, in the 1950s young people were probably on average poorer than they are now. Perhaps they were also more narcissistic, or equally narcissistic as they are now. Were there also fewer parties? If not, this suggests there is something wrong with the theory.
My question to the GP is: do they believe that there are no time periods like the 1950s in my example, which might raise doubt about their theories? If they think there aren't any, is it because we have never been so poor and narcissistic as we are now? Or is it because there have never been so many parties at any prior time period, as there were in the golden age they identified where we were at our least poor and narcissistic (whenever that might be)? If there are such periods, why isn't that part of their theory? If 'the 1950s' were different, what is it that makes them different, and is that reflected in the theory?
It should be clear here, that any variable which has moved monotonically in one direction for ever and so is currently at a global extreme, is correlated with every other, especially if it is a phenomenon which can't be measured in formal units (like narcissism or fear of strangers). Saying that (satirizing the GP here) 'we have never had so many smartphones, and we have also never had so many allergies, therefore allergies are caused by smartphones', is laughably easy to dismiss, for a number of reasons.