Obviously a radio broadcast of a sporting event requires an commentator or two to tell the listening audience what is going on. But why do TV broadcasts of sports almost always use commentators? What is the point of having someone describing the event when viewers can see for themselves?
Personally I am a frequent viewer of American football on TV, and I almost always find commentators take away from my viewing experience rather than add value to it. In fact I will often mute the volume to escape the annoyance of the commentators - but then I miss the actual sounds of the game, from the players and from the crowd. Overall the presence of the commentators can be quite frustrating.
I remember during the Olympics in Athens, the video of many less popular events (such as cycling) was viewable via online streaming, with no commentators, meaning the only audio was the sounds of the athletes and the spectators - and it was awesome! It felt less like watching on TV and more like really being there in person. So why isn't a similar approach taken for more conventional sports broadcasts? Why are commentators so frequently used in TV sports?