Economic growth and getting better at tennis
Can get physically bigger, stronger, and faster. Weight room. That will make you better at tennis, to a point. But ultimately the gains from that run out, if only because physically it gets harder and harder to get stronger and stronger or faster and faster. There are limits in terms of time, nutrition, and genetics. You can’t sustain getting better and better just by physical training.
Level differences. Those who train more will be stronger, etc.. and better. But they won’t grow faster.
Feedback loop of a sort here. Physical ability translates into better tennis to some extent - but not perfectly - and better tennis translates into more effective physical training. Think of being very efficient, saving energy, so you can do more physical training. But that loop has diminishing returns, so ultimately you can’t keep it going.
Different that practice, which is using your physical tools but working on making them more efficient. Better shots, better understanding of placement, better technique.
Illustrates that even non-rival improvements in technique cost rival time and effort. Nothing is for free.
Where scale comes in is through the fact that you can copy others. Observing others play or how they play makes you better. You can adopt their ideas. Also scale matters because the bigger tennis gets, the bigger the rewards to being good. If you can make money playing, you’re going to spend more time/effort thinking about how to get better and practice more. Scale also matters because more people means more likely to get outliers who are great, improving experience for everyone.
Playoffs and competition
Competition. Like tweaking playoff rules. If you just take most popular teams and put them in the final, it’s better for ratings, but ultimately no innovation as why bother? If you make it harder to get through playoffs as you get better, then again, less incentive to work on game.