^ I really don't think the Davis Cup is any danger and I hardly think we can "do away" with it - as you put it
The Davis Cup has been running for years, the Laver Cup is very new - I'm sure the Davis Cup will run for years, although they may perhaps alter the format one day.
Sorry, bit of brain disconnection there! I meant alter its format to make it less strenuous for the top players to compete in. As for the Laver Cup, we already have the Hopman Cup so I don't see how another one would hurt given that neither are ATP events and so are challenging but more relaxed options.
Having watched some of the highlights, which I enjoyed, it did seem rather odd to have Fed and Rafa on the same side of the court!