So using a vpn is purely if your hiding something while on the net correct ?

Using a VPN service isn't useful for much more than hiding your location or getting past something your provider is blocking.

A VPN itself is otherwise a useful tool for combining remote networks to act like a single network, and is often hosted by businesses or even individuals to access internal resources, like shared network drives and intranet pages, or even printers, though the latter is usually on accident.

Concealing your origin anyhow. There are more actors than “the state”. Predatory advertisers and hackers alike may be interested in your unique home IP address. Let’s just say a VPN adds a layer of abstraction which must be breached before your origin may be found.