This logic is sus. Just because we cannot have a oerfect system doesn't mean we shouldn't have it at all. Like alcohol age limitations, they can be worked around and wont ever be 100 percent perfect but I see regularly teens bouncing off the register at my local store.

So the metric should be case by case for each proposed solution. Most of things proposed are no good, but that doesn't mean there is not a sensible solution out there to limit net for teens.