That's not the only point. Web apps can have far lower performance or battery utilization than real native apps for one thing. If you care about the environment or your battery life use a compiled app, not the web.
I see now what the parent poster meant. He said a web app can have lower performance and battery utilization. He meant lower performance and higher battery utilization. From the context it was clear and I misinterpreted it.
Especially on iOS more so than Android apps since there is no JVM like environment.