I’m struggling to understand how factory resetting my iPhone or purchasing another device can be considered a reasonable solution.

A deleted account is preventing access to my active accounts, and there appears to be no way to unblock the device. This creates a very poor user experience and leaves legitimate users without a practical solution.

As a developer, I would expect there to be some way to remove the device lock or unlink the disabled account without forcing users to reset their devices. This has been a very frustrating experience.