[throwaway6532]

Good luck replacing water.

This perspective also assumes enough creativity and capital available to do this will always there. If you're going to need to develop potentially more complex and expensive technology it's going to need a certain level of complexity and population to support that complexity available. With birth rates being below replacement level it seems population of young people is heading down generation after generation. So... I'm not so convinced this assumption will always hold. In fact, it's a concrete example of a negative feedback loop kicking in and correcting the status quo for us as in order to have a society capable of such a level of innovation it has to be structured such that it's population refuses to reproduce in sufficient numbers.