I've seen many instances where a company or organization generates and uses a PGP keypair for a team or group of people. Most likely they all have a copy of the private and public keys on their individual machines or sign on to central server and use the
gpg utility there (all knowing the shared secret key password).
What happens when one member of the team leaves the company? What if they go rogue upon departure? Assume that they copied the secret/key to their personal USB thumbdrive before you revoked access to the central server or watched them delete their keypair.
It would be extremely inconvenient and impractical to revoke and reissue the "team" PGP key every time someone left the company (image a team of 10+ people).
What do companies currently do? Do they just ignore the possibility an ex-team member will act with malice?
For a realistic scenario, let's talk explicitly about a
firstname.lastname@example.org mailbox with PGP key
"Example Inc. Security Team" <email@example.com> (0xAAF00F00) where Bob, Alice, and Charlie (the team) have access to the mailbox, and PGP public/private keypair.
The mailbox and PGP key is for receiving reports of high-severity security vulnerabilities to Example Inc. and the team leverages encryption and message signing for correspondence with security researchers.