Volunteerism isn't "post-scarcity". If you're fed and watered by providing value in a capitalist system, and choose to spend your spare time volunteering, that's great, but it's nothing utopian. Volunteerism is a free choice of work in exchange for a price of £0. That's regular old capitalism at work.
If you could just generate energy out of the ether and use it to materialise food and anything else you might want, for example, that would be post-scarcity.
If you could just generate energy out of the ether and use it to materialise food and anything else you might want, for example, that would be post-scarcity.