Ignore whether or not we actually agree with the tragedy of the commons for a moment.
If free land anyone is allowed to use is inevitably going to result in individuals acting in their own self interest depleting the resources of the fields and ultimately bringing about collective ruin… Does that not apply to like… All of capitalism? On the planet?
The capitalists are incentivised to act in their individual interests, and they will do so to the ultimate collective ruin of the entire planet.
That is the tragedy of the commons expanded to an international scale, and if one believes in the tragedy of the commons then one must also believe in the other.
The commons must be centrally controlled and managed in the collective interest.
The market must be centrally controlled and managed in the collective interest.
The argument is supposed to be that it would be irrational to wreck or cannibalize your private property for short-term gain when doing so would eventually leave you without productive property. That kind of behavior is only stopped to happen (according to The Economists) with property held in common, as nobody has an incentive to spend resources safeguarding the future of something that isn’t their sole demanse. As we know, capitalism is totally rational and not at all preoccupied with short term gains at the cost of long term destruction, so this has to be right!