I heard a story about a guy in the UK who has spent a fortune to make his "biological substrate" look like Kim Kardashian's. Just because humans can think of doing all kinds of things, it doesn't follow in the least that (1) nonhuman things vaguely analogous to humans exist elsewhere in the universe; and (2) these things would want to do anything to themselves like what you imagine.

Basically this whole ET idea has turned into a waste of time for people who have the IQ's to do more productive things with their minds. ET's live beyond our world, they live forever, and they can assume different "substrates." For a site devoted to exploring cognitive biases, why don't you explore how this ET fantasy has basically become a replacement for god beliefs rationalists would reject in other contexts?