Consider two possible ways the world might be (or that you might suppose the world could be):

1. There is no afterlife for human beings. You live and you die and that's it.

2. There is no afterlife for human beings in the conventional sense, but people are reincarnated, without any possibility of remembering their past lives.

From the subjective point of view of conscious experience, these two situations are subjectively indistinguishable. Are they objectively distinguishable? That depends on the "metaphysics" behind the situation. Perhaps they are, and perhaps they aren't, and if they aren't, then we are not talking about two possible situations, but only one. But let's suppose they are, and that you find out that number 2 is true.

Do you really think you have any reason to be happier than if you found out that number 1 was true? There are certainly subjectively indistinguishable situations where I would prefer one to be objectively the case rather than the other, but it is not clear to me that this is one of them. In this particular case, I don't see why I should care. Likewise, as suggested by James Miller's comment, I don't see why I should care whether I am objectively the same person as I was yesterday, or if this is just a subjective impression which is objectively false. And if I don't care about that, then creating something that would remember being me is just as good as continuing to exist.