During televised sporting events, why must the broadcasters be speaking at all times?

Watching any televised professional sporting event, there is someone on the TV talking to you the entire time. When one guy can’t talk anymore, the other guy just gets right in there without missing a step. There’s hardly more than 1 second at a time where someone isn’t chattering. Why does this happen? Would the game somehow be worse if we didn’t have to hear them going off constantly?