Claim
Marketing to 'Gen Z' or 'Millennials' as a monolith is a 15-year-old mistake the cartoon world has been parodying since 2015. Buyer behavior within a generation varies more than between generations; the brands that win drop the demographic shorthand and target on actual behavior, channel, and purchase context.
Mechanism
Generational segmentation is a heuristic that feels intuitive in the boardroom but breaks at the funnel because it doesn't map to purchase intent. Behavioral and contextual targeting maps directly to intent, which is why brands that switch see conversion lift even with the same creative.
Conditions
Holds for consumer brands with rich behavioral data. Fails when the only available data is age and demographic — there generational shorthand is at least better than nothing.