A slightly compressed JPG of an oil painting is still, at least for purposes of intellectual property rights, not distinct from the original work on canvas. Sufficiently complex and advanced statistics on a work are not substantially different from the work itself. It's just a different way of storing a meaningful representation.
These LLMs are all more or less black boxes. We really cannot conclusively say one way or another whether they are storing and using the full original work in some form or another. We do know that they can be coaxed into spitting out the original work, though, which sure implies it is in there.
And if the work of a human that needs to be fed is being used by one of these bots -- which is pretty much by definition a commercial purpose given that all the relevant bots are operated as such -- then that human should be getting paid.