alt Hacker NewsYou’ve described NAS in general. It’s more than just file system. Plex gives you Media Library indexing, web app, mobile and TV apps to play content from your NAS, from anywhere in the world (it even includes Relay, in case you don’t have public IP or accessing NAT traversal).
Even with public IP, it brokers an HTTPS certificate for you, which many smart TV platforms and OSes require for operation nowadays.