In a closed system, you could grow the commons until there's no scarcity anymore, and thus no tragedy either. This stops working once some "entrepreneur" figures your commons is their arbitrage opportunity, and opens the system to the outside world.
I'm taking this disgusting train to it's logical conclusion. Seeking VC to start my "mouthsharing" company, where you can hire someone to pre-chew your food up for you, like a baby bird.
See, I like the peer-to-peer idea, but if you're going to be centralized anyway (via the service), why not have your own sourcing resources as well? Team up with waymo or whatever self-driving taxi services are around, rent out a small chunk of the trunk to store a good selection of cutlery and consumables (teabags, salt and pepper, sriracha packets, etc. etc.).
> In a closed system, you could grow the commons until there's no scarcity anymore
I don't know what your definition of "closed system" is, but I can assure you the only way the dining hall gets more forks is if they enter the system from outside. Unless it's a dining hall at a fork factory :)
