I agree. Life is rare in the universe, and andro-encephalic civilizations are rarer still.

I suspect that no civilization has achieved interstellar travel.

Most likely, there is no practical way for andro-cephalics to engage in interstellar travel. Hence, all planetary civilizations are original. The chances for an unmanned, unguided, sub-light speed interstellar probe encountering a planet capable of supporting life are remote.

It is reasonable to suppose that there are other civilizations in this universe, but they are most likely remote and unreachable. In light of this, we are alone, even if we are not alone.