That's not true. As with all game theory payouts, it's not saying that a Nash equilibrium is inevitable, it's saying that to avoid it you need incentives outside the game, it's saying that the incentives of the game itself don't suffice.
In terms of "the tragedy of the commons", that outside incentive is usually public shaming in smaller communities, or rules and laws in larger and more anonymous communities. If you look at shared resources across history and cultures, you usually find communities enforce very strong outside incentives against spoiling the commons instead of just relying on the kindness of strangers.
In terms of "the tragedy of the commons", that outside incentive is usually public shaming in smaller communities, or rules and laws in larger and more anonymous communities. If you look at shared resources across history and cultures, you usually find communities enforce very strong outside incentives against spoiling the commons instead of just relying on the kindness of strangers.