Actually they do, just in combination with other ways of granting citizenship. To pick Italy off your list, if a child is born in Italy and it’s parents are unk

Actually they do, just in combination with other ways of granting citizenship. To pick Italy off your list, if a child is born in Italy and it’s parents are unknown or unable to transfer their citizenship(stateless, unknown citizenship etc) the child becomes an Italian citizen. Most modern first world states provide pretty solid protections for children born on their soil.