We’re not alone. We’re surrounded by alien intelligences on our own planet. Other species of animal. We’ve only just glimpsed the tip of the iceberg regarding their cognitive abilities. As for other worlds, I think it’s extremely unlikely we’re completely alone in the universe. Life MUST have evolved somewhere else. What that life is like is anybody’s guess but if we treat it with the same contempt we treat non human intelligences here, we’re fucked.