Enter LLMs training off that data. It looks similar on the surface, but if you think about the balance of cost and benefit it becomes clear it is no longer balanced. The training algorithms and models are closed source, and come at a hefty usage cost. AI companies saved hundreds of billions of dollars of paying humans to help train their algorithms by taking advantage of an open system that was open on with another kind of balance in mind.
So in short the work was offered for free within a specific kind of relationship. Now a powerful outsider is steamrolling and taking advantage of that existing open dynamic.