Imagine OpenAI, Anthropic &co having to compete by hiring [thousands] of their own talent to help training their commercial models.
Another thing is attribution. Even a book that was re-published illegally can be easily attributed to its author. What happened is the exact opposite: no attribution, not even a notice, just obfuscation that strips away any traces of the original ideas and original work. Imagine piracy websites and trackers just dropping first few pages that name their authors, and publishing "the book you are looking for". This is exactly what happened.