You made two arguments for why they shouldn't be able to train on the work for free and then said that they can with the third?
Did openai pay for the material? If not, then it's illegal.
Additionally, copywrite and trademarks and patents are about reproduction, not use.
If you bought a pen that was patented, then made a copy of the pen and sold it as yours, that's illegal. This is the analogy of what openai is going with books.
Plagiarism and reproduction of text is the part that is illegal. If you take the "ai" part out, what openai is doing is blatantly illegal.