I do try to somewhat follow longtermism. Though I am not certain that the philosophy is ideal. They take our personal human values that are instinctual and lack scientific evidence, e.g. human life and happiness are objective goods. If you think in a cosmic sense, it's impossible to argue that these must be true. They then apply expected value and other logical frameworks that are not in our instincts but are instead coming from a rational / non-instinctual perspective. The space in which I believe that a human is objectively valuable is not the same space in which I make cosmic arguments about what is inherently good.