Life is a zero-sum game in many ways.
There are some obvious ones. For example, you can't create energy out of nothing, some form of matter must be converted into energy.
Then there are some less obvious ones. There is always going to be a fixed amount of stupidity vs clarity. There is going to be as much personal stress and personal liberation. There is a fixed level of scepticism vs doubt. There is going to be as much atheism as religiosity. And for every member of the vegetarian club, there is going to be a friend of the abattoir.
I don't think there is any practical use for these observations. They're just something to be aware of, and perhaps, to remind oneself to stop worrying about the world losing it's balance, and to stop arguing with it.