The concepts raise the standard of policy development. Consider how much easier it is to discuss a proposal thanks to 'The Tragedy of the Commons'. Those few words serve as a shorthand for a dynamic. Without it you might need to spend half an hour stepping people through the dynamic each time you wanted to refer to it, and you would lose people along the way.
The “invisible hand” is also something that actually does exist and is straightforward to explain. It’s the tendency individuals making decisions in their own self-interest to find others with compatible self-interest as the motivation to make a trade. Every mutually self-interested transaction adds up to a total gain for the overall economy because each side makes the trade precisely because they judge the other’s offer to be of higher value to them. The key to demystifying the observation is the insight that “value” is a judgement made by individuals in relation to their own lives, not some inherent property that can be determined apart from individuals value judgements.