If materialism is true, then I think Nietzsche is right: truth is not a value; life-enhancing illusions are to be preferred. If truth is out of all relation to human flourishing, why should we value it?
I think that somewhere Aquinas defines truth as the conformity of the mind to reality. Knowing how things are would seem to be better than not, even if that knowledge be grim. I also suspect that immortality of any sort is something we ought not to bother ourselves with.