In many ways, web conferencing offers even less human connection than audio conferencing.
The video aspect of web conferencing is rudimentary, and the quality is far from high definition. A web conference really only provides a way to show or share data, and its audio component typically goes in one direction—from the presenter to the audience. Audience members often have no way to communicate with the presenter during the conference even if they wanted to, except by sharing questions through a text interface.
It's cumbersome because users first have to visit a website and then dial in to hear the audio. At low Internet speeds or on a cell phone, the process can be frustrating. If you've ever tried to have a phone conversation in a bad cell area or over a slow Internet connection—well, you get the idea.
From a presenter's point of view, there is no way of knowing if your conference is successful. The best video conferencing service allows you to see the body language and facial expressions of your participants to gauge how receptive they are to what's being discussed.