It’s not hypocrisy. A billionaire is orders of magnitudes richer than a millionaire. A millionaire doesn’t have nearly the same capacity to do overwhelming good as a billionaire does.
A millionaire who chooses not to use their money to help isn’t good but a billionaire who chooses not to use their money to help is decidedly evil.
Much like how you not giving half your sandwich to a homeless guy isn’t good but a restaurant that throws out perfectly good food at the end of the night directly next to a homeless shelter is decidedly evil.