Yeah you definitely can become a billionaire without being a scummy person, just not trough business. You need to be an artist or athlete.

As you say, she’s a scummy person, so you have no way of knowing that she only became a billionaire because of the books.

Most of the Harry Potter stories are stolen/copies of either existing young adult novels or existing mythology. There’s very little original material or concepts. All writers borrow from other writers, but Rowling is just barely better than a plagiarist.

Rowling became a billionaire

Google says her net worth is £820 million. Not a billoonarrr.

You don’t become a billionaire without exploiting so many people and then hording those riches to yourself. You’ve already been corrupted by that point.

I think for most people, they become an asshole on the way to becoming a billionaire. You don’t make that kind of money without exploitation and plundering. The only exception I could think of would be if they inherited the money. And even so, if you inherit that kind of money and don’t give out a good chunk of it, you’re still scum imo.