Many of the security flaws of other companies are actually exposed by Google's Project Zero. The charitable view would be that they put more effort to fix bugs

Many of the security flaws of other companies are actually exposed by Google's Project Zero. The charitable view would be that they put more effort to fix bugs that they have found, the cynical take would be that they extend their own deadlines indefinitely. This would of course explain only some classes of bugs. One story I do remember though was that the introduction of Google Buzz leaked your contact list to all of your contacts.