Why isn't the comparison meaningful? Aaron broke the law and circumvented protections, Anthropic broke the law and circumvented protections. Regardless of if Aaron broke into a network closet or anthropic broke DRM, anthropic took explicit action to receive knowingly stolen goods.
The CFAA is for unauthorized access to a computer system. Downloading from libgen isn't unauthorized access that can be prosecuted under the CFAA.
Say you have a network. You want to keep someone out of it. The tool for that is the CFAA.
If you have a book, and you want to stop someone from reproducing it, the tool for that is copyright.
They cover different domains. If you're not breaking into a network, you're unlikely to be charged under the CFAA.