Do you believe Tanjiro…

given that someone else survived the curse

You forget to tell that that someone that survived was literally the chosen of the gods and he was born with the mark, his body was different than any other person since birth, his body was literally made to endure the damages of the mark

Tanjiro body is the same as every one else, Yoriichi was unique in every way.

Tanjiro died young same as every other demon slayer that used the mark