See, the fake Beth stuff is what I love about this show.
Take a sci fi premisse: that you can make a indistinguishable clone with all your memories that can replace you.
Now ask ethical questions based on this sci fi premisse: Is it okay to abandon your responsabilities when you can be reasonably sure that an exact copy of you will make the same decisions you would? Is it okay to not do "your" job in this sci fi context that a thing that for all intents and purpose is you is still doing the job in question?
And then you couple that with a couple of more metaphysical questions: Does it make a difference? Does it matter?
It might matter a little to Rick because he knows he is dealing with a clone, but it is also irrelevant given he has interdimensional issues with that same subject.
It matters to real Beth because she knows that she is not a clone and that, when given the choice, she decided either to stay or go.
It doesn't matter to fake Beth or the children because they don't know and have no way of knowing they are not dealing with the real thing. It is a clever play on the Leibnizian topic
Identity of indiscernibles
Yet, almost none of it is spelled out.
It is a simple scene where Rick presents the parameters of the problem and then leave th rest to the public.
Perfect, concise, 5 seconds, I can laugh at it, I can create a conspiracy theory on youtube, I can try to convince people it has something to do with Leibniz, I can take it, leave it, whatever.
Perfect. Beatiful TV right there.
Compare it with Rick literally speaking about how she doesn't care (which is not true given the story of her character) because she is smart (which isn't false, but Beth is, you know, real world smart, not supergenious smart).