Xinyu is not afraid, but she knows that this is the ending, so she will not make any choice, because no matter what, she will lose him eventually, and losing him will not make people feel scared. It is just that she is unwilling to do so. After all, it will be fruitless, so why bother?
If there is love in the world, the world will grow old. Knowing that it will end like this, why should we go through this again?