Access control decisions usually come down to convenience, security level and how the credential is managed day to day.
Cards and fobs
Quick to issue and easy for staff to use, but they can be shared or lost, so lifecycle management matters.
PIN codes
No hardware to issue, but codes get shared. Best combined with another credential on sensitive doors.
Biometrics
Tied to the individual and cannot be handed over, which suits restricted areas — with attention to enrolment and hygiene requirements.
Mixing credentials by door
A practical design uses cards at general entrances and stronger credentials at restricted rooms rather than applying one credential everywhere.