Nothings ever quite that simple anyway. V-brakes ARE THEMSELVES a form of cantilever brakes - actually the Registered name for Shimano's version of linear pull cantilever brakes. Even cable pull isn't consistent. Mini V-brakes will have a ratio similar to traditional cantis and less mechanical advantage than V-brakes eith longer arms. And the now discontinued Shimano parallel push V-brakes have every bit as much braking power as many disc brake systems.
Tire, fender or rack clearance is usually more of a reason to end up with one system over another. Traditional cantis give the most clearance and can handle any tire/fender combination that'll fit on a bike. And they happen to be compatible with the pull ratio of most road brake levers.