Empy, where's your twin MK ? There's no such thing as post-scarcity- it exists in SciFi perhaps. Resources are finite & even if resources were self-sustainable via recycling cadavers & excrements into food, there are also uniquely human traits that would prohibit a "post-scarce" ecosystem. The science, economics, academia, philosophy doesn't support it.
A couple examples of academic theories:
1. The universe isn't designed to progress under equilibrium. Effectively life dies without imbalance and chaos.
2. Ethics prohibit a lot of sustainable scientific efficiency.
3. It takes more expertise and machines to convert raw material into a commodity. Machines need fuel & fuel is a finite resource & why the world is at war for it at present.
4. All living things have a decay rate, even the sun. The more we recycle something, the less it can be of quality to the point it would be detrimental. Same goes with gmo foods to clones. Clones have half life less than original, gmo foods are harmful if it's been modified too much.
5. We don't eat monkeys because they're genetically similar to us. Recycling biomatter for consumption to recycling fossil fuel eventually does more harm than good.
I could go on.
The only SciFi notion I think is viable and most likely the future of humanity is to send a cohort off to migrate to a planet & start a new civilisation there. At most civilisation on earth has maybe a couple hundred years left before the ozone layer is completely ripped apart, rising sea levels & earth uninhabitable.