And if you want to look at it that way, I can say you are leaving a collection of stamps, you are preserving little snippets of history and culture from around the world and through the years. In my case, I might be leaving sick replays of me beating SMW2 World 1 in record time, for other's to watch in awe as I do over other speedrunners' work.
If you kind of look at it, everything can preserved and enjoyed by those coming after us. Stamp collection too in many ways is preservation of history. A game of chess with all its moves recorded, or an epic game of tetris.
Or take food for example. No body can taste what you cooked, but you can write down the recipe and ingredients to the very last gram and people can enjoy it forever.
So you spend your time creating something for other people to consume, then note that the act of consuming it is useless?