>>211612858Ever since the industrial revolution, each cohort experiences a very different upbringing as society rapidly transforms around them. These shifts might have been contained to ~30 periods before the mid-20th century, but now things severely deteriorate every 15 years or so. This results in distinct character traits as those cohorts reach adulthood and begin participating in society. And it's not about what kind of music or fashion is popular or whatever. It's about society and the economy fundamentally changing, which significantly alters one's upbringing and the adult they become. People who grew up in the 1990s-2000s were very different from those who grew up in the 2010s-20s at the same age.
For example, I was born in the 80s. I got to work jobs since I was 14, moved out at 18, bought my own place by 27 - all these things were typical for my cohort. But people born after 2000 do not have these opportunities so their lives take a very different trajectory, resulting in a completely different group of people.