When observing current children, we compare our biased memory to the present and a decline appears.

From Kids these days: Why the youth of today seem lacking by John Protzko and Jonathan W. Schooler.  From the Abstract:

In five preregistered studies, we assess people’s tendency to believe “kids these days” are deficient relative to those of previous generations. Across three traits, American adults (N = 3458; Mage = 33 to 51 years) believe today’s youth are in decline; however, these perceptions are associated with people’s standing on those traits. Authoritarian people especially think youth are less respectful of their elders, intelligent people especially think youth are less intelligent, and well-read people especially think youth enjoy reading less. These beliefs are not predicted by irrelevant traits. Two mechanisms contribute to humanity’s perennial tendency to denigrate kids: a person-specific tendency to notice the limitations of others where one excels and a memory bias projecting one’s current qualities onto the youth of the past. When observing current children, we compare our biased memory to the present and a decline appears. This may explain why the kids these days effect has been happening for millennia.