Even a minimal amount of curation - e.g. generating multiple options and choosing the "best" one, or applying a filter where you don't post some of the generate

Even a minimal amount of curation - e.g. generating multiple options and choosing the "best" one, or applying a filter where you don't post some of the generated data because it's bad - results in valid, usable training data, because the distribution of that slightly curated data differs from the generating model's distribution in exactly the direction which the curating human found most important. So even if we all do use AI, the training data will get generated unless we don't get involved at all and AI does literally everything 100% solely on its own, at which point we could concede that it probably doesn't need any more training data.