Te default authentication mode that bugzilla login uses are regular HTTP cookies. At least for bugzilla.redhat.com that means that they expire after few days, requiring logging once more, after a command that was using python-bugzilla failed. That's a bad user experience.

When bugzilla login notices that the instance it is connecting to is Bugzilla 5, it should suggest to the user the use of API key instead of the HTTP cookies.

something like bugzilla login --api-key that asks for the API key and creates necessary configuration files would likely be most user friendly (short of generating the API key automatically).