1Password is used at a lot of medium-small businesses where employees have shared credentials (usually these smaller businesses don't have built-out identity management systems to cover everything with SSO).
A place I worked before would store SSH keys for build machine base images (AWS AMIs) in 1Password. It wasn't worth the trouble trying to setup SSO since the machines rarely needed accessed and only by a handful of people to troubleshoot/manage them.
It's also common to share credentials when you're working with small SaaS that don't support multiple users or SSO. In addition, sometimes business integrations will have fixed credentials (like the SSH key to upload reports to a business partners SFTP server). People still need access to the keys for troubleshooting and debugging.
