If a candidate avoids all contact with the media, they end up preaching to the choir. There are too many voters in the US that do not do any research, instead relying on the media for information.
The fact that the media is only too delighted to take advantage of the fact is secondary. They do serve the purpose of exposing some voters to candidates and information they would otherwise never encounter.
To reach voters who are unwilling to do their own investigations, candidates have to use the media. But they do not have to do so within the narrow rules preferred by the media itself.
Have a great day, FRiend!