@Infrapink @jasongorman @tymwol I think both things apply. One reason that Eliza was so convincing is that it was "mimicking" a psychological therapy session. Where having your ideas repeated back to you is common and a good way of making connection.
It fulfilled peoples expectation of a session. Like faces on toast fulfill peoples expectations. All of the so called "intelligence" is actually in ourselves.
Chat tools can help us work out the answers ourselves sometimes - a well know developers trait. But mostly, it gives us what we expect, and that is good enough for us.