That might have something to do with it. But gen-z seems to have more a purity culture than millennials and gen-x had.

Many are very into exercise and fitness from a very young age. Control their diets. Sleep super early, get up early.

They are going less to clubs (and shitty dive bars). Doing less drugs. Having less sex.

You can say its all because of money. But broke teenagers and young adults of previous generations had their fun, went out, destroyed their bodies. You know, it can be REALLY cheap to get fucked up and well, get fucked or fuck.