Why is Norton VPN so terrible?

Half the time I can use VPN for an hour or so, then it bogs down and I lose Internet access until I kill it. Today I was trying to pay online with a credit card on a public network but could not because VPN had crapped out. I finally killed it and used my phone as a hotspot and then was able to complete the transaction. This is a frequent issue. Yes I’ve rebooted, reinstalled, etc. That’s not the problem. Your service is the problem.