You may well not need one for this case. The main advantage for you would be that Webroot WiFi Security uses our Brightcloud Threat Intelligence to help filter the web connection on connected devices, which may act as add additional layer of protection from viruses and malicious websites.

The benefits of using a VPN in your scenario depend largely on how much you trust your ISP, and how much you value your privacy.

Websites (and - more importantly - the advertising and third party services embedded within them) can often geolocate visitors with a surprising degree of accurracy based on their IP address. This can be used along with data from your device and browser to build a unique profile of you and your interests. Connecting via a VPN means your traffic eggresses onto the internet at the VPN server location and not your home address which can help make it more difficult to be tracked online. For this to be effective you should combine it with a privacy focused browser like Firefox, tweak your privacy settings like Do Not Track and consider extensions such as Ghostery and NoScript.

ISPs can almost certainly a lot of information about your browsing habits as well - even with HTTPS/TLS it is likely they can see your DNS queries and at the very least will have knowledge of the IP addresses you are connecting to. Encrypted DNS is being to roll out by default in the United States on Firefox but for most users either won’t be supported by their browser or is something that they will have to opt into. Even with HTTPS/TLS the packets need to identify the location where they should be sent and although the data itself is encrypted the ISP will know where it is coming from and roughly how much is being sent. Think of it like a sealed envelope. Although the postal carrier doesn’t know what is inside the envelope, it knows that Party A is sending data to Party B based on the addresses on the outside, how often and roughly how much from the size and weight.

Where the user is using a VPN all of their traffic is inside the encrypted VPN tunnel and the ISP no longer has that visibility - although you have to trust the VPN provider as they have the same access as your ISP would have done where you are connecting directly through them.

Other use cases are to avoid geo-restrictions on content - for example many US news sites block European users from accessing them due to GDPR regulations. Some users use VPNs to avoid censorship on content such as news or political content that might be restricted in a locality (although this as a technical measure only, and doesn’t change the legal restrictions in force). These are both use cases of VPNs but I should note we don’t sell WiFi Security specifically for either purpose.

Lastly the VPN may be of benefit were your router ever to be compromised or a hostile device plugged into it - it is often possible to view all traffic for all devices on a network by using a tool like Wireshark -  but the latter is less likely in a physically secure environment like a home.

With all that said, the cases we are primarily marketing WiFi Security for don’t appear to apply in your case, and you may not find the benefits outweigh the cost.