[throwawayzRUU6f]

The economy as a whole is definitely not a zero-sum game, there's plenty of evidence of that.

However, that doesn't in any way invalidate the claim that parts of the economy are in fact zero-sum. How large are those zero-sum parts - 10%? 20%? 40%? 80%? Nobody truly knows. Needless to say, the optimal survival strategy in a world of 80% zero-sum is vastly different than in the 10% world.

Also, although there's no data to back it up, I believe the zero-sum games as a proportion of our society are growing, and quite rapidly at that. It's a very worrying trend.