Sure, but fair use is rather narrowly defined. You must consider the purpose, nature, amount, and effect. In the case of scraping entire bodies of work as training data, the purpose is commercial, the nature is not in the public interest, the amount is the work in its entirety, and the effect is to compete with the original author. It fails to meet any criteria for fair use.
The work is not reproduced in its entirety. Simply using the work in its entirety is not a violation of copyright law, just as reading a book or watching a movie (even if pirated) is not a violation. The reproduction of that work is the violation, and LLMs simply do not store the works in their entirety nor are they capable of reproducing them.
It doesn’t have to be reproduced to be a copyright violation, only used. For example, publishing your Harry Potter fanfic would be infringement. You’re not reproducing the original material in any way, but you’re still heavily depending on it.
