I think I understand why 'authentic' is beloved by AI - it's effectively meaningless.
It can mean 'genuine', as in 'carbon dating and handwriting verification prove that this oil painting is a genuine William Shakespeare'.
It can mean a good fake, as in 'this is an authentic Melton Mowbray pork pie' even though it wasn't made in Melton Mowbray.
Or it can mean completely bogus, as in 'The Rajah Tandoori Restaurant provides an authentic Indian dining experience' even though the staff aren't Indian and the dishes were invented in Birmingham.
AJ