This is from Douglas Adams’ Dirk Gently’s Holistic Detective Agency, for those (like me) who haven’t read it.

https://en.wikipedia.org/wiki/Tragedy_of_the_commons

The tragedy of the commons is the idea that when a resource is shared and can benefit the individual at a cost to the community, it is rational for the individual to overuse the resource, even though this collectively leads to the depletion of the resource for everyone