[throwaway2245]

I draw the exact opposite conclusion from the same premise.

Octopuses (cephalopods) are our direct relatives; we have physical contact with them; we easily observe to be intelligent; we know them to communicate with each other, and yet we can't meaningfully communicate with cephalopods.

How do we have any hope of communicating with an extra-terrestrial intelligence?

[billiam]

TBH we haven't really tried very hard to communicate with cephlapods. A few dozen scientists max have worked on this in the last 50 years.