A VPN is an encrypted tunnel between your computer and the internet  at large. They exist to allow employees access to internal intranets of a  company to do work remotely.

That's it.

They are merely a tunnel and not a means to keep your data/metadata  private. Any VPN provider you use can see what you access, how often,  and for how long. It's not hard either; I do this in my own home from  time to time with a program called Wireshark; cause I'm a nerd.

Just being on a VPN does not make your data private.