There are only "old, weak, sick and pregnant" seats on the bus. Should I eat?

It suddenly occurred to me that if there are only elderly people, sick people, disabled people and pregnant women on the bus, should we do so in principle? If you don't sit, it's a waste of resources. You must wait until the old, the sick, the disabled and the pregnant have a vacancy. However, if you give up your seat, it means giving up your seat in order to highlight the old, weak, sick and pregnant, but it also means that passengers who don't take the old, weak, sick and pregnant seat don't have to give up their seats, which is inconsistent with our values of giving up their seats to those in need, and has become "only those who sit in that seat need to give up their seats." I always feel that the position of the special seat for the elderly, the sick and the disabled is very embarrassing, which prevents those who are willing to give up their seats, but can't stop those who are unwilling to give up their seats.