As one of those authors (3 books in this case) I'll just point out:
Most authors don't own any interesting rights to their books because they are works for hire.
Maybe I would have gotten something, maybe not. Depends on the contract. One of my books that was used is from 1996. That contract did not say a lot about the internet, and I was also 16 at the time ;)
In practice they stole from a relatively small number of publishers. The rest is PR.
The settlement goes to authors in part because anything else would generate immensely bad PR.
Just like nobody cares[0] that American big tech stole from authors of millions of books.
[0] Interestingly, the only ones that cared were the FB employees told to pirate the Library Genesis and reporting back that "it didn't feel right".