I understand the logic here and would probably concede a few points if I heard your argument fully. However, many people have children and I believe that puts skin in the game, so to speak. Most people are not solipsistic and have at least some degree of empathy for others, even if they don’t know these people or these people aren’t even born yet. Think about student debt for example. Some people may want their student debt payed off, but they don’t think it’s right that other taxpayers are paying their personal debt. These taxes would be raised in the future as well. I think there are actually a ton of actions people take because they are keeping one eye out on the future. Think of the principle as to why problem go into debt or make investments. They’re expecting a bigger reward at the end. I think ethics can operate on a similar principle, if not one to one. I would argue if people threw out any sort of personal investment in the future would destroy the present as people would simply do what they need to do to get ahead, future be damned.

Sorry this was a bit of a ramble