Playing tennis isn’t the most efficient way to learn to play tennis.
How do you learn to play tennis if you have never played it before? You could just jump right in. Find somebody who has never played the sport and learn while you play them. Your game will be terrible and your technique will be clumsy, but you will enjoy yourself.
An alternate approach is to do drills. Playing tennis involves gripping the racket firmly, learning good playing form, footwork and correct positioning on the court. A stroke could be broken down to lobs, smashes, slices, drops and drives, both on the forehand and the backhand. Finally, there is serving – the hardest part to learn. The most efficient way to learn to play tennis is to practice each of those pieces and learn them individually before integrating them within a game.
The first approach is fun, but inefficient. The second approach is boring, but efficient.
Playing a game is an inefficient way to master it. To learn a new skill is to strike the right balance between inefficient play and efficient drills.