I decided to look up masking studies online yet again, to see if anyone had actually gathered the information that used to be scattered here and there from this and that study, and then analyzed it scientifically. Do masks do anything positive enough to make us wear them? That is the question at hand, after all. I already know on a personal, empirical level that they have negative effects on respiratory and mental health. My search yielded this, from last July:
The foregoing data show that masks serve more as instruments of obstruction of normal breathing, rather than as effective barriers to pathogens. Therefore, masks should not be used by the general public, either by adults or children, and their limitations as prophylaxis against pathogens should also be considered in medical settings.