I agree with pretty much all of that, and I’d thought of it before, but I especially hate the obsession with generations. It’s totally nonsensical. Because of my age, I have a special shared affinity with people who were in kindergarten when I started with college, rather that people who were in some of the same classes as juniors when I was a freshman?
I do remember growing up thinking it was weird that we called people “Generation X” but our generation had no name. And then I started hearing the term “Millennial” when I was in my 20s and it took me years to realize a) that it applied to me b) that it was a term like “Baby Boomer” or “Generaion X” and not specifically a term of derision that people would only ever apply to themselves in self-deprecation.
The only one of those generational terms that doesn’t belong in the trash is “baby boomer.”

He touches on this in the video, but I do think that part of the loss of decades has to do with the fact that a big part of how we talk about 20th century decades is in terms of of popular culture like fashion and music, and those don’t work very well for the 21st century. But regarding the substitution of traumatic events as cultural markers, 9/11 and the pandemic both came at the right time for that.