But moral/ethical, and/or sufficient compensation?
IMO (and it is just opinion), the damage GenAI does to IP value happens when, and only when, an AI is good enough to make some human unemployable, and that happens to all e.g. novelists around the same time even those whose IP was explicitly excluded from training the model. So, twist question: is it fair to pay a UBI to people who refuse to contribute to some future AI that does end up making us all redundant? (My answer is "yes, it's fair to pay to all even if they contributed nothing, this is a terrible place for schadenfreude").
Conversely, mediocre regurgitation of half-remembered patterns that mimic the style of a famous author cannot cause any more harm when done by AI than when done by fan fiction.
Right now these models are pretty bad at creative fiction, pretty good at writing code, so I expect this to impact us before novelists, despite the flood of mediocre AI books reported in various places.
Other damage can happen independently of IP value damage, like fully automated propaganda, but that seems like it's not a place where compensation would go to a copyright holder in the first place.
Sufficient compensation? If AI works out, nobody will have any economic advantage, and UBI is the only fair and ethical option I am yet aware of for that.
It's what happens between here and there that's messy.
I think funding UBI studies and lobbying for that sort of thing is a public good, but is entirely unrelated to -- and does not make up for -- wholesale copyright infringement.