It does work! If malware tries to call out it's blocked! The granular control is gone because Windows 8 to 10 had changed the way vendors are able to use the Firewall Controls: Outbound connections fw control in Win 8/ Win 8.1 - Webroot Community
So Webroot doesn't use the new API's so why duplicate them. And yes all vendors have to use Windows API's in there Firewall for Windows 8 to 10.
Other vendors have firewall controls that work with the current Windows API's. Webroot WSA does not.
The way Webroot promotes WSA for W8/10, the average person who reads their website, literature, etc, expects to have functional firewall controls on W8/10.
The bottom line of it, is that there is very little outbound network control with Webroot - because it relies upon Windows Firewall.