Also: They don't really work in other countries or demographics. Generational bins presume that shared experiences form a somewhat comparable outlook on life.

I am a Xennial. I grew up in Western Germany. Are my life experiences the same as someone who grew up in Eastern Germany, experienced the fall of the Wall and all the economic and political disruptions afterwards in their formative years or by witnessing their family's experiences? My life didn't change, the country got a little bit bigger. Theirs in many measurable and unmeasurable ways. Are we the same generation?

And that was a peaceful revolution. Other countries weren't/aren't such lucky.