Not to be rude but, google is free:

https://www.google.com/search?q=are+millenials+heavy+drinker...

Well, your first Google result is a blog post that makes my point.

> For example, baby boomers are the generation with the most dramatic increase in harmful alcohol abuse. In contrast, Gen Z prefers the sober lifestyle as they are known to consume alcohol much less than any of their older counterparts, including millennials.