From Don't use VPN Services by Sven Slootweg...
Don't use VPN services.
No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.
Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.
Because a VPN in this sense is just a glorified proxy. The VPN provider can see all your traffic, and do with it what they want - including logging.
But my provider doesn't log!
There is no way for you to verify that, and of course this is what a malicious VPN provider would claim as well. In short: the only safe assumption is that every VPN provider logs.
And remember that it is in a VPN provider's best interest to log their users - it lets them deflect blame to the customer, if they ever were to get into legal trouble. The $10/month that you're paying for your VPN service doesn't even pay for the lawyer's coffee, so expect them to hand you over.
But a provider would lose business if they did that!
I'll believe that when HideMyAss goes out of business. They gave up their users years ago, and this was widely publicized. The reality is that most of their customers will either not care or not even be aware of it.
So why do VPN services exist? Surely they must serve some purpose?
Because it's easy money. You just set up OpenVPN on a few servers, and essentially start reselling bandwidth with a markup. You can make every promise in the world, because nobody can verify them. You don't even have to know what you're doing, because again, nobody can verify what you say. It is 100% snake-oil.
So yes, VPN services do serve a purpose - it's just one that benefits the provider, not you.
The entire article is worth a thorough read but those are the most relevant bits.
VPNs are an easy way to make money off scaring people into engaging in security theater.