If you think I'm being optimistic about UBI, I can only question how optimistic you are about your own position receiving wide spread support. So far not even most artists stand behind anti AI standpoints, just a very vocal minority and their supporters who even threaten and bully other artists that don't support their views.

It’s not about “analysis” but about for-profit use. Public domain still falls under Fair Use.

I really don't know what you're trying to say here. Public domain is free of any copyright, so you don't need a fair use exemption to use it at all. And for-profit use is not a factor for whether analysis is allowed or not. And if it was, again, it would stagnate the ability for society to invent and advance, since most frequent use is for profit. But even if it wasn't, one company can produce the dataset or the model as a non-profit, and the other company could use that for profit. It doesn't hold up.

As it stands, artists are already forming their own walled off communities to isolate their work from being publicly available

If you want to avoid being trained on by AI, that's a pretty good way to do it yes. It can also be combined with payment. So if that helps artists, I'm all for it. But I have yet to hear any of that from the artists I know, nor seen a single practical example of it that wasn't already explicitly private (eg. commissions or a patreon). Most artists make their work to be seen, and that has always meant accepting that someone might take your work and be inspired by it. My ideas have been stolen blatantly, and I cannot do a thing about it. That is the compromise we make between creative freedom and ownership, since the alternative would be disastrous. Even if people pay for access, once they've done so they can still analyze and learn from it. But yes, if you don't want your ideas to be copied, never sharing it is a sure way to do that, but that is antithetical to why most people make art to begin with.

creating software to poison LLMs.

These tools are horribly ineffective though. They waste artists time and/or degrade the artwork to the point humans don't enjoy it either. It's an artists right to use it though, but it's essentially snake oil that plays on these artists fears of AI. But that's a whole other discussion.

So either art becomes largely inaccessible to the public, or some form of horrible copyright action is taken because those are the only options available to artists.

I really think you are being unrealistic and hyperbolic here. Neither of these have happened nor have much of chance of happening. There are billions of people producing works that could be considered art and with making art comes the desire to share it. Sure there might only be millions that make great art, but if they would mobilize together that would be world news, if a workers strike in Hollywood can do that for a significantly smaller amount of artists.

Ultimately, I’d like a licensing system put in place Academics have to cite their sources for research That way, if they’ve used stuff that they legally shouldn’t, it can be proven.

The reason we have sources in research is not for licensing purposes. It is to support legitimacy, to build upon the work of the other. I wouldn't be against sourcing, but it is a moot point because companies that make AI models don't typically throw their dataset out there. So these datasets might very well be sourced. One well known public dataset LAION 5b, does source URLs. But again, because analysis can be performed freely, this is not a requirement.

Creating a requirement to license data for analysis is what you are arguing here for. I can already hear every large corporation salivating in the back at the idea of that. Every creator in existence would have to pay license to some big company because they interacted with their works at some point in their life and something they made looked somewhat similar. And copyright is already far more of a tool for big corporations, not small creators. This is a dystopian future to desire.