Are Previous Prophets A Hujjah For Us?
You’re confusing hujjah with itnam-e-hujjah. Hujjah simply means proof. Prophets use these proofs to perform itmam-e-hujjah (culmination of proof). The stories of prophets mentioned in the Quran are those that it’s direct addressees were already aware of. Quran mentions them as evidence – and that evidence is as true for us as it’s direct addressees.