But I essentially agree with you, the destruction of all white collar and creative jobs is something the proponents hand-wave too easily with vague mention of UBI as a thought-terminating cliché rather than a real policy proposal.
(Myself, I'm in a strange position with doppelgängers, because I simultaneously want real human connection and keep getting disappointed with many of the real humans).
I believe the proponents think it will make content more profitable, especially in the sense of concentrating the wealth that can be extracted from content creation. Related, there’s a desperate attempt to redefine code as “content”, at least implicitly, so that it can fall under that umbrella as well.