I feel for the psychological safety aspect, I really do. There are some cities in the US where the public transit system gets underutilized and hosts more bad behavior. From personal experience, MARTA seems rough after COVID, and psychological safety rightfully becomes a huge factor in avoiding the public transit system. But your second to last sentence is pure hysteria. If you feel that unsafe in Boston or NYC, I'd advise you to drive armed too, because you could experience trouble from a "random crazy" with road rage.