> Why even make that argument in the first place then?
Making an argument doesn't require to describe every step to it, if I told you could use your GPS to navigate to work, you're not gonna ask me how to launch a satellite in space.
> It's the equivalent (following your logic) of saying that "it would be nice if we were living in an utopian society with no material scarcity"
Copyright have nothing to do with material scarcity, neither does UBI, that is about money, a man made social construct, not a material thing.
exactly as you say, an argument for UBI doesn't necessarily need to mean retreading the whole history of UBI designs and legislatures, it just means someone would like to UBI exist without necessarily having to be an expert on how to implement it. I wanted to eat some sushi today and I didn't start questioning myself "well how would you evolve sushi rice starting with a wild rice cultivar", i just went to the store and bought it and now i'm fine. there are experts for that sort of thing and I leave it up to them. I guess if someone doesn't realize there are experts for topics then that betrays they think they are an expert with everything.