Throwing, Catching, Kicking, Movement, Dribbling, Skipping, Hitting, Blocking.
Fundamentals are not Forehands, Backhands, Volleys, and Serves. Those are what we call the actions that all of the fundamentals make up and what we see when we watch tennis players. When the fundamentals are worked out in an ideal way, forehands, backhands, serves, and volleys are easy to perform and players are set up to play great tennis.
Of course the fundamentals can be developed playing all types of sports, especially ball sports. However, only when they are practiced on a tennis court, with a tennis racquet, against other players will they coordinate to make for a strong tennis player.