OP is referring to the j-curve historically seen in studies about drinking. Because researchers didn't control for people who stopped drinking after years of abuse or people who couldn't drink because of other health issues, it looked like having 0 drinks per day led to worse health outcomes than 1-2 drinks per day. Because of that, many health organizations spent decades telling people that 1-2 drinks per day was better for you than 0 drinks per day.

Someone finally controlled for those variables a few years ago, and the j-curve vanished. Most health organizations now say they're is no amount of alcohol that is safe to consume.

So it's got nothing to do with Gen Z drinking habit specifically, and the science has been corrected since. But a lot of people still internalized and parrot the "1-2 drinks is healthy" thing.