Vaglogins do not make your system impenetrable. They make your system inconsistent for the attacker while remaining invisible to the honest user. And in cybersecurity, inconsistency is the only real defense.
This sounds counter-intuitive, but Vaglogins often improve the user experience for low-risk tasks. Because the system trusts the context, it can completely remove passwords for "View Only" mode. Users can check their inbox or calendar without any login ceremony. Only when they attempt to delete an archive or change a password does the system demand heavy authentication. Vaglogins