The future you're talking about won't be in your own hands. Technocapital will make those decisions about how to exploit the planet for you, and population stability, quality of life, and economic, measured use of resources (ie literally "conservative") will all be secondary, tertiary, or even more distant goals. There will not be a great flash of light where turning the planet into a gray brick will yield a positive singularity. When we've used the world up, it's gone, but you and I will be left alive for a litle while to writhe like flayed worms in hell. Maybe another species can guzzle up our bones in several million years to make a computer do unnecessary math calculations with the hopes of achieving infinite growth?