How are Chrome extensions less powerful than Firefox extensions? Also, Safari extensions are perfectly capable of reading and stealing your password on banking

How are Chrome extensions less powerful than Firefox extensions? Also, Safari extensions are perfectly capable of reading and stealing your password on banking websites, which is what everyone seems to be concerned about. In fact, there's a warning about that in the Safari extensions user interface: "Can read sensitive information from webpages, including passwords, phone numbers, and credit cards."