Bill Gates: "[RFK Jr.] wrote a book saying that Tony Fauci and I kill millions of children

Bill Gates: "[RFK Jr.] wrote a book saying that Tony Fauci and I kill millions of children and make billions of dollars with vaccines."

"People can judge for themselves whether that's correct or not."

If it's not correct, why didn't Fauci and Gates sue RFK Jr. for defamation? 🤔