"One of the primary factors in a consideration of fair use is how transformative a derivative work is..."

Yes.

But in nearly every case, the original source can be attributed. In this case the source was made from many inputs, all stolen under the original conception of copyright. Admittedly so, not an opinion.

So how can it be a derivative work if the 'artist' cannot show what the original work looked like? You can steal my car, but chopping it up and transforming it doesn't get a pass.

If the origins are then considered to be computer generated, then it is not only disallowed copyright, it has no legal status whatsoever.

"Consider a movie reviewer who uses clips of the movies he is reviewing. He may monetize his reviews, but still be covered by fair use because his use is transformative and doesn't compete in the same market as the movie."

Not talking about clips for reviews. If the movie reviewer took "clips" from the film and made a NEW film from them - one that told a different story altogether fromt the original - they would not be able to get away with it.

Because source material matters.

Obfuscating it behind walls of algorithm, I do not believe, doesn't make it legal.