You don’t need to have an additional VPN service, but it does r:
- Give you additional privacy
- Allow you to appear to be in a different geographical location for geoblocked services.
For my needs, here’s a post I did somewhere else that may give you some ideas 
1. Home
*I don’t want to VPN my entire network or my family would not be happy. I have a gl.inet travel router between my television/notebook and my main router running a US VPN (that can be turned on and off via a physical switch) so I can get US Netflix
*I have used them as small, cheap, power efficient WiFi extenders to deadspots in the house
2. Travel
*I normally travel with around 3 devices ( phone, tablet, notebook), it’s a pain in the *&se to have to connect all three devices to the free hotel WiFi (as well as a security risk). All three of my devices are attached to the WiFi LAN produced by my travel router. When I reach a hotel I just connect my travel router once to the hotel WiFi and my devices attach to the travel router WiFi without doing anything. Move hotels, just reattach the travel router.
*Because my devices are now on a different subnet, I have some level of protection from the open public WiFi
*For extra protection I can run a VPN on my travel router and all my devices attached are VPNed
*I take a Chromecast with me when I travel. Because there’s no ability to get to a captive portal with a Chromecast which some hotels have, I just attach my Chromecast to my travel router WiFi
*If the hotel restricts the number of devices you can attach to their public WiFi, using the travel router only presents ONE device attached and all the rest of my devices just attach to the travel router.
*I’m overseas and want to use Iview/SBS/Netflix to watch a geoblocked website to get my local content. Turn on my VPN and away I go.
*Extends out point 2. I have my family with me each with at least 2 devices, again I don’t have to do anything to their devices as they just attach to the travel router automatically and once we move hotels again, just attach the travel router and don’t have to do any tech support
*I have a shared USB/Microsd card with movies, music on that everyone can access via the travel router
*Travelling with friends I give them access to the microsd so they can dump their photos onto the shared SD card both for backup and to share pictures
Hope this helps