Ask the same mothers if they would call a woman being paid to have a baby and then give that baby to the person/s paying, a mother? I'll ask you, what do you think? Obviously you say yes but the law calls them surrogates at which birthing people, that is gives birth, seems appropriate. Maybe that's a bit too much for your mind to comprehend?
Quick definitions from Macmillan (
mother
)
noun
▸
your female parent. People sometimes call their mother Mom or, especially if they are children, Mommy.