It's the relatability to the audience that mandates they have human faces. ... because humans can only interpret the facial expressions and emotions of other human faces.

Star Trek was never meant to be Sci-fi so much as soap opera in space.

> because humans can only interpret the facial expressions and emotions of other human faces.

Arrival was pretty good in showing actually alien aliens (while falling into the trope of godlike aliens).

Watch some octopus videos. You may get a sense of a certain connection, empathy, between sentients that transcends our physical forms.

Counter-example: https://orville.fandom.com/wiki/Yaphit

I don't really think that's a counter-example, the face and body animations are all very human-like.

Farscape did pretty well with having relatable characters played by puppets.

I'd agree, but the faces of all the regular characters were very human-esque. Even Pilot's face was puppetted to react vaguely human.

Still a very big departure from humans with masks.

Not just puppets but muppets!

https://muppet.fandom.com/wiki/Farscape

Star Trek was ever meant to be Sci-fi (search how Roddenberry and Asimov became friend). Soap opera in space is what CBS want it to become because it is so mush easier to write for (see Kurtzman-verse).

Maybe, but in animated things (like rick and morty) they, occasionally, have aliens that are vaguely essentially anthropomorphic animals and give those expressions.

So it's not entirely.. human. My point being that we can have the expressions of a human face on a non-human face

> My point being that we can have the expressions of a human face on a non-human face

To bring up the example of the octopus again, you can still get some sense of "expression" like anger etc. when they change their skin colors, without having a relatable face at all.

Or something more common: Dogs wagging their tails, cats pointing their ears, and so on.

Dogs and cats only work for us because we're already so familiar with those.

Aren't we already there?