Why do billionaires use Swiss banks?

AMERICAN PLUS Bank National Association 6 Arlington State Bank 2 ARROW Bank National Association 11 BANK OF NY MELLON TC National Association 14 BankStar Financial 5 CLEAR FORK Bank National Association 1 CONSUMERS National Association National Bank 4 DLP Bank 18 Fidelity Bank of Texas 5 FINWISE Bank 22 FIRST INTRST Bank 10 FIRST KEYSTONE Community Bank 9 FORESIGHT Bank 15 Grant County Bank 5 National Iron Bank 11 Petit Jean State Bank 4 STATE STREET B&TC 26 SUMMIT State Bank 5 T Bank National Association 5 Unity National Bank of Houston 7