Cohorts are tailor made for the use-case where the lifecycle of the snap is managed externally, such as by a Charmed Operator or manually by an sysadmin, especially where upgrades need to be coordinated across multiple machines. It complements well the option for the snap to self-manage its upgrade via the gate-auto-refresh hook for the other use-cases, such as Desktop applications, tools like microk8s or multipass, IoT devices, etc.