The only time I use a VPN is when I'm traveling and using free hotel WiFi which for me isn't that often. I used Mullvad VPN during a recent trip to Boston, spent less than $6 for the month, and cancelled the service when I got back home. I have never had issues connecting to any websites but it is an extra server to route all of your traffic through, so it can potentially be slower. To directly answer your question, nope, I haven't heard of PIA.
In my opinion, the main benefits of using a VPN are privacy related. You can keep your browsing from your ISP because all they see is encrypted traffic between sites and the VPN server. If you don't trust your ISP to not sell your metadata to the highest bidder, then a VPN is a good way to avoid that. Just make sure to pick a trustworthy VPN provider because they're the ones who will have that data instead of your ISP.
In terms of general security, most of the web now uses HTTPS anyway, so all of that traffic is already encrypted and secure. Transmitting things like credit cards and passwords isn't improved by using a VPN. Some VPN providers have additional security measures that protect you from visiting harmful sites or downloading harmful files, but a little common sense about those things is a lot more effective.
There are some things that I think should be higher priority for online security:
Don't reuse your passwords. Create secure passwords and use a password manager to remember them for you.
Even though it's a pain sometimes, use 2 Factor Authentication wherever it's supported. The type that uses an Authenticator app (Authy, Microsoft Authenticator, Google Authenticator, etc) is better than relying on text messages, but the text messages are a lot better than a username/password alone.
If privacy is your main concern, install an ad blocker extension for your browser. uBlock Origin is a good example. An unbelievable amount of tracking happens as you browse the web, and there's a lot of money in knowing who you are as an ad target. A VPN generally doesn't do anything about this, because it's all happening in your browser which is communicating with the site you're visiting. Encrypting the traffic through a VPN only means it's being securely sent directly to Facebook, for example. An ad blocker will shut down most of that tracking and keep it from being shared with the sites you're visiting.
EDIT: I didn't realize this before, but Mullvad VPN, and probably other VPN providers include ad blocking and anti-tracking features which would be similar to what uBlock Origin does. uBlock Origin is free, though.