Even worse, there isn’t a next generation near the size of millennials. Part of the reason that millennials took over while Gen X didn’t was because of the size of the relative generations.

You’re also running into the issue that culture has become a lot more fragmented due to the Internet. You can present a millennial culture where most people may be aware of other subcultures even if they weren’t a part of them. I don’t know if that is going to happen for Gen Z or Alpha.