Especially in shared Wi-Fi networks that means usually better performance, and less problems with rejected connections to whatever service, or certain type of traffic not permitted, DNS requests that are redirected, and so on.

I don't usually use VPN for privacy, since these days you have HTTPS that protects the communication, but they are super useful if you want to use a network that is not yours without issues.

Beside that these days we may not have a file server, but we have a ton more of devices that we want to access when we are not in our network, without relying on a cloud (and thus giving away our privacy): IP cameras are the perfect example, I don't want the video stream to pass trought the cloud, I can connect in VPN to my home network and access the video stream. Beside that there are a ton of "smart" devices inside your home these days.