We might be alone in the Universe. In one sense, aliens are but a conceptual substitution for angels and demons.
But, like belief in angels and demons, I don’t see much harm in belief in aliens and people searching the heavens for life. Personally? I think we may have to redefine life to include things we don’t think of currently as life. I think it’s around us in unexpected places. But maybe they’ll find something. and that’ll be pretty awesome if they do.