I think this overstates the interest in drugs among Zillenials and Gen Z.
Most people in our cohort tend to follow a "you do you" philosophy that cuts both ways - if you choose to or choose not to partake in marijuana or alcohol, that's your choice.
Stuff like "marijuana" or "alcohol" isn't viewed as cool or uncool, it's just viewed as a yet another consumable like coffee or sugar.
Same way some people choose to cut down on coffee and others are coffee fiends, it's similar with booze and weed.
Personally, I find that older generations have an unhealthily polarized view on weed and alcohol consumption - they are split between the "weed cures everything" and "weed is the devil's lettuce" camps.
Heck, even this thread has tinges of judgement about how younger generations just don't care one way or the other about weed as if weed consumption is a core part of being young.