Keyboards can access every app that you use a keyboard in, so basically everything from your passwords to credit card can be logged.

This isn’t true on iOS - when you’re entering details on password fields it goes to the default keyboard precisely so the third party ones can’t log your passwords. Many people think this is a “bug” and often complain about third party keyboards on iOS being shit and buggy because of this, when in reality it’s a safety and security feature - a good one at that IMO.