If intelligent aliens arise due to evolution they'll likely be fairly close to humans in mindspace compared to the entire size possible. In order to reach a minimal tech level, they'll likely need to be able to cooperate, communicate, empathize, and put off short-term gains for long-term gains. That already puts them much closer to humans. There are ways this could go wrong (for example, a species that uses large hives like ants or termites). And even a species that close to us in mindspace could still pose massive existential risk.