They may be teenagers, but they're not wrong to attend to the minutiae; whether for selfish or for social reasons, that awareness may be all that is keeping them and their loved ones alive. It is cruel and unjust and wrong that they alone are attending to the minutiae of masking, but here in the United States our social support systems often require them to bear that responsibility, as the adults responsible for them often do not.
Like their parents, who could end up hospitalized, or worse? Seems like a good reason to be concerned.
If you're in a school: you're catching omicron, and unless all of the students are wearing at least PAPR hoods all the time, everybody is catching it. Allowing yourself to get worked up about seeing a kid with his mask down in the bathroom is insane.