Haha, the inverse question is: why have it if it doesn’t help you with anything? Regardless, it's a layer that contributes to the 99.xx% effectiveness of real-world protection.
The first layer is TrafficLight. If that misses, then it’s the web traffic inspection. Without the web traffic inspection, then it’s going to be file read/write/execution, just like MD. If you go on the BD forums when people protest "TrafficLight didn't catch it," the answer often is, BD blocks it (at the traffic inspection) anyway.
I’ve never had such problems with BD or Avast regarding the web traffic inspection either—it’s pretty non-intrusive until you start thinking, oh… it sees all my encrypted traffic, including my password that isn’t additionally encrypted.