When you use a VPN, your ISP can no longer throttle your connection because they cannot see what kind of traffic you are sending. All they can see is that you are connected to a VPN To Bypass ISP Throttling and all of your traffic is encrypted so they cannot inspect it. This means that you can use as much bandwidth as you want without having to worry about your ISP slowing you down.
There are many other benefits to using a VPN as well, such as increased security and privacy. However, the ability to bypass ISP throttling is one of the most important reasons to use a VPN. If you are worried about your ISP slowing down your connection, then a VPN is the best solution.