For me it made sense how he died refusing to relent and go back into Yuji and choosing to die a vile mess as a curse rather than accepting humanity and love. Yuji can show him what love is and has but naturally he would never accept it. However, as a Sukuna stan did they HAVE to make him look like that? If it was me writing I would have made him 'human' again (without the curse markings or in his weakest form) to represent humanity as it would parallel yuji and them have him reject it but the message would be the same.