Is it true at 21 1/2 wks gestation theres no way of saveing a baby?

i went into preterm labor and delivered my baby girl at 21 1/2 wks but the dr.s wouldnt even try to save her saying it was imposible at this stage but in 3 wks they could have but she lived for an hr and a half is it true they couldnt have done anything that it wasnt even worth a try?