When it comes to utilitarianism vs deontology, one example that gets brought up time and time again is the case of someone in the desert who is thirsty and needs to steal water from a water vendor in order to live. That violates common rules among men, but the cost benefit analysis says that this is justified.
I don’t know the right answer to this problem, but I can say that a market would solve this problem. Markets incentivize some people to save for others who are reckless. It’s a beautiful yin and yang that forms. Some people are old and don’t need money at the moment, so they let others who are still growing, borrow the money temporarily. that’s teamwork.
When it comes to the strangers in the desert, the person with the water intends to sell it to thirsty people. The fact that there are thirsty people int he desert shows that there is a market to bring water there. If water keeps getting stolen, that reduces the insentive to “save” water.