A lot of what feels like "boomer" pop culture was actually the greatest generation. Remember, the boomers were the hippies and Happy Days crowd, not the Leave it to Beaver Crowd. But you may be right that the time frame is shrinking. New technology, especially social media, is making everything move faster. Arguably measured by culture, generations are getting shorter.
Both can be true. The Greatest Generation came home from war and immediately invested heavily in home and family, which included a bunch of family friendly media which they partook with their Boomer kids. I think this was both for psychological reasons/how the nation saw itself at the time, and also the simple ease of reaching more people by catering to disproportionately populated demographic. At the other end, shows that were music competitions where people came up and sang renditions of Beatles/Dylan/Motown were major primetime advertiser sinks up through maybe 2010-12 (so, up to about a decade ago, as Tony alludes). Now, that's Boomers watching shows along with their X, Mill, and Xenial children and grandkids, just like the Greatest had done with the Boomers. Who gets 'credit' or whatever is going to be subjective. From my perspective, I think in a way both ends do count for Boomers because the decision about what to show was significantly influenced by keeping that demographic watching/listening/reading. *Keeping this U.S.-specific based on my own knowledge base. Anyone with other nations' perspectives, feel free to add that.
The entire concept of specific cultural generations is just trying to apply solid framing to a nebulous concept of certain demographic groups and how they influence both popular culture and society as a whole. Part of it, I feel, is that people simply started giving new names to demographics more rapidly. For instance, 'Boomer' got a solid 20 years (usually seen as DOB 1945-1965), but Gen X got a nebulous 14-17 years, depending on who you ask (but few put it all the way to 1985). Is that because the demographic group ended there, or was it because after ~1979-1982, people started coming of age during the turn of the millennium, and people started wanting to talk about 'Millennials?' It's hard to say. Certainly it's good reason not to use the demographic generations as concrete markers and take with a grain of salt anything that tries to break things down by generation as though they were.
A generation's impact doesn't extend through its first 20 years, it extends from its teens through its thirties-ish, when they are the target of the people making the entertainment (the generation before). For example, the D&D that GenZ loves is mostly made by GenXers, who grew up with it and are nostalgic for it. It's why you get remakes: the people able to make music or television or movies or comics finally end up in the drivers seat at entertainment companies.
Seems like an argument that athletes are better than other people, since they have superior bodies and superior minds.
