RebYidd:
I am not against drinking. I am against the shikrus that is incompatible with fulfillment of mitzvos. Someone noted earlier that if one’s drinking renders them unable to remember to daven Maariv and recite Kriyas Shema properly, then it is not a mitzvah at all. Ad delo yoda does not mean incapacitated or unable to function. Returning to the OP, teenagers that have the capacity to stop before approaching the status of risk, fine. Those that cannot do not get the dispensation that they are fulfilling a mitzvah and are therefore exempt. I cannot speak for generations ago, as i obviously was not there. But most of today’s teens lack the maturity of judgment to handle this well. The tragedy stories are told afterward, but are outdated in preparation for the following Purim.
Do you know how to set an appropriate limit for drinking among teens so that no one gets near danger? I do not profess to know the answer, and a standard one won’t really do. So someone needs to exercise that judgment and create the needed boundaries. And the Poskim are clear that one who cannot drink without danger should not.