The primary use case is as a perimeter firewall separating different security zones from each other. We separate several zones, such as Internet Of Things (ie. cameras and several sensors), Internet-facing DMZ, internal networks, and guest networks from each other.
Also, we use the VPN feature to create Site to Site tunnels between branch offices and the headquarters. Threat Prevention features including IPS, Anti-Bot, Threat Emulation, and Threat Extraction and are used to secure our users from being victims of several threats.