Yes pretty much. Most ISP's just buy access to the cheapest routes which are not always the fastest. I rent servers that are connected to the fastest routes and send the customers game traffic through them. This often results in lowering the latency by a significant amount.

The other thing the VPN does is allows people to choose which region they want to play on. For example, in PUBG, when you launch the game it pings all of the different available regions and selects the one with the lowest latency. This is not always ideal as there may not be any players on the closest servers and you end up playing against a bunch of bots.